Method for testing yield performance of material cake formed by crushing of material bed and extrusion crushing device
By using the squeezing crushing device for the yield performance test of the squeezed crushing device in the ingredient bed, it solves the problem of insufficient testing performance testing performance in the existing technology, and realizes the appropriate adjustment of the strength of the cake and the improvement of equipment stability.
Patent Information
- Application Number
- CN202411811358.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-10
- Publication Date
- 2025-01-28
AI Technical Summary
The prior art lacks an effective test method for the yield performance of the material cake formed by the material bed crushing, which leads to the inability to accurately judge the difficulty of the material cake and the stability of the equipment, and the material bed crushing equipment is prone to vibration and energy loss.
Provide a yield performance test method for the ingredients formed by the shattering cake, including compressing the loading material under the preset loading stress and loading speed by squeezing the crushed device, calculating the density and yield strength of the cake, and using density and density and density and density and density and density and density and density and density and density and density and density and density and density and density and density and density and density and density and density. The extension relationship of the yield strength adjusts the equipment parameters of the bedding bed to ensure that the strength of the cake is appropriate and easy to dissipate.
The rapid and accurate testing of the yield performance of the cake is achieved, helping to regulate the crushing equipment parameters of the bed, avoid the loss of equipment vibration and energy, and ensure that the strength of the cake is appropriate and easy to disperse.
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Figure CN119375033A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of material bed crushing in cement grinding industry, and in particular to a yield performance testing method of material cakes formed by material bed crushing and an extrusion crushing device. Background Art
[0002] In the 1980s, high-pressure material bed crushing was put into practice as a new method of crushing mineral materials with the development of new materials and grinding equipment such as roller presses and vertical mills. Under high pressure conditions, the material particles in the material layer squeeze each other, and strong stress is generated inside each particle. When the stress reaches the breaking stress of each particle, these particles are crushed one after another. Because the energy required for crushing is directly applied to the surrounding of the material particles, its effective effect is greatly improved compared with other forms of crushing operations. The crushed materials have the characteristics of high fine particle content, many microcracks and low unit crushing energy consumption, with significant energy-saving and consumption-reducing effects, which conforms to the development trend of "more crushing and less grinding" technology and is a key technology to improve crushing efficiency.
[0003] The material is crushed by the roller press, vertical mill and other material bed crushing equipment, and the crushed material is squeezed to form a dense material bed, that is, the material cake. The material cake can be dissociated and dispersed under the action of external force. The roller press and other material bed crushing equipment have certain requirements for the strength of the discharged material cake: it can form a material cake with appropriate strength (which can be broken by hand) to facilitate uniform unloading and loosening. If the material cake is too loose or no material cake is produced, it may be due to insufficient pressure, too large roller gap, insufficient and uneven feeding, etc., indicating that the material bed crushing has not fully played its role; if the material cake is too hard, not only is it difficult to fully break up the subsequent material cake, but also indicates that the pressure exceeds the critical pressure too much, resulting in energy loss; in addition, the material layer may collapse during the extrusion process due to the force exceeding its yield strength, which in turn causes the vibration of the roller press and other material bed crushing equipment, affecting the crushing efficiency.
[0004] In the current actual crushing operation, the cake is broken up with a special mechanical external force breaking mechanism and breaking equipment, but the strength of the output cake is not tested. The cake strength can objectively judge the difficulty of breaking the cake from the mechanical properties, and it is of great significance to the research on the stability of the equipment bed. However, there are not many related studies on the yield strength of the cake.
[0005] Laboratory bed ballast crushing test is an effective method to study the bed crushing characteristics of solid materials using a small amount of samples. The roller press is the product of the transition from intermittent bed crushing in the laboratory to continuous bed crushing. Under certain conditions, the bed ballast crushing test can be used as a laboratory simulation of bed crushing equipment such as roller presses. Therefore, we can also expand the yield performance test of the cake produced by bed ballast crushing under laboratory conditions. Summary of the invention
[0006] In order to solve the problems existing in the prior art, the present invention provides a yield performance testing method for a material cake formed by crushing a material bed and an extrusion crushing device, which solves at least three main problems:
[0007] 1. A split-flap self-locking material bed ballast crushing device is provided, which can non-destructively remove the material cake formed after the material is crushed by the material bed;
[0008] 2. Provides a test method for the compressive yield strength of materials / cakes, using the fitting relationship between the density of the cake and its yield strength to solve the problem of characterizing the overall yield performance of the material / bed;
[0009] 3. According to the characterization results of yield properties for different materials, adjust the parameters of the roller press, vertical mill and other material bed crushing equipment in the cement industry to avoid violent vibration or excessive energy loss of the material bed crushing equipment, make the material bed crushing equipment run stably, and make the generated material cake have appropriate strength and be easy to break up.
[0010] The technical solution adopted by the present invention to achieve the above technical effects is as follows:
[0011] The present application provides a method for testing the yield properties of a material cake formed by crushing a material bed, comprising:
[0012] Step 1: compressing and loading the material under preset loading stress and loading speed conditions by using an extrusion crushing device to obtain a material cake;
[0013] Step 2: Measure the thickness of the cake and calculate the density of the cake;
[0014] Step 3: Place the cake in a pressure testing machine to perform a compression yield strength test and generate a corresponding stress-strain curve;
[0015] Step 4: Find the yield point in the stress-strain curve and determine the yield strength of the cake.
[0016] Optionally, in some embodiments of the present application, in step one, the preset loading stress range is 5-200 MPa, and the preset loading speed is 1-55 mm / min.
[0017] Optionally, in some embodiments of the present application, in step three, the pressure testing machine includes a stress strain capturer, which captures the stress and strain change values in the stage of extruding the material to form a cake and the stage of conducting a compression yield strength test on the cake.
[0018] Optionally, in some embodiments of the present application, in step 4, the yield point search and judgment process includes:
[0019] When the yield point of the stress-strain curve is obvious, the stress value corresponding to the yield point is selected as the yield strength value;
[0020] When the yield point of the stress-strain curve is not obvious, the point corresponding to the slight plastic deformation is selected to characterize the yield strength value of the cake.
[0021] Optionally, in some embodiments of the present application, steps one to four are repeated under different preset loading stress conditions, and after the cake is formed, the thickness of the cake and its compressive yield strength are recorded in each test, the density of the cake is calculated based on the thickness of the cake, and the yield strength and density are linearly fitted.
[0022] Optionally, in some embodiments of the present application, different loading stresses are set with stress gradient values, the maximum stress value is taken within each stress gradient value range, and each stress value is made into multiple groups, each group includes steps one to four.
[0023] Optionally, the present application also provides an extrusion and crushing device, including a tray, a bottom gasket is arranged on the tray, an inner ring petal component and an outer ring locking component are arranged around the bottom gasket, the inner ring petal component is located inside the outer ring locking component, so that the outer ring locking component extrude and limit the inner ring petal component, the inner ring petal component cooperates with the bottom gasket to form a pressure chamber, and a pressure head is arranged on the top of the pressure chamber.
[0024] Optionally, in some embodiments of the present application, the pressure head is connected to the pressure testing machine, so that the pressure testing machine pushes the pressure head to squeeze the pressure chamber.
[0025] Compared with the prior art, the beneficial effects of the present invention are:
[0026] Through the proposed method of the present invention, the optimal density range of the required yield strength of the material cake can be quickly obtained. When analyzing the materials squeezed by the material bed crushing equipment in the cement industry, it is only necessary to set two to three groups of stresses with different differences and large differences, so that the corresponding density and yield strength values can be obtained in the material bed ballast crushing test and the compression yield strength test. According to the fitting law of density and yield strength, the yield strength corresponding to the material cakes of different densities can be quickly obtained. BRIEF DESCRIPTION OF THE DRAWINGS
[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.
[0028] Figure 1 A schematic diagram of a split-flap self-locking cake extrusion and crushing device provided in an embodiment of the present application;
[0029] Figure 2 A cross-sectional view of a split-flap self-locking cake extrusion and crushing device provided in an embodiment of the present application;
[0030] Figure 3 A top view of a split-flap self-locking cake extrusion and crushing device provided in an embodiment of the present application;
[0031] Figure 4 A schematic diagram of a stress-strain curve generated in the compressive yield strength provided in an embodiment of the present application;
[0032] Figure 5 A schematic diagram of a fitted regression line of yield strength and cake density provided in an embodiment of the present application;
[0033] Figure 6 A schematic diagram of a fitting regression line of yield strength and cake density provided in another embodiment of the present application;
[0034] Figure 7 A schematic diagram of the overall process of the yield performance testing method provided in an embodiment of the present application.
[0035] Description of reference numerals:
[0036] 1. Press head; 2. Outer ring locking component; 3. Inner ring petal component; 4. Bottom pad; 5. Tray. DETAILED DESCRIPTION
[0037] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments of the present application, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the protection scope of the present application. It is understood that the drawings are only provided for reference and illustration, and are not used to limit the present application. The connection relationship shown in the drawings is only for the convenience of clear description and does not limit the connection method.
[0038] In the embodiment of the present application, a yield performance test method of a material bed crushing material cake is provided, and the test method is mainly performed by an extrusion crushing device, such as Figure 1-3As shown, the extrusion crushing device mainly includes a tray and a pressure head, wherein a bottom gasket is arranged on the tray, and the material can be placed on the bottom gasket. An inner ring petal component is arranged around the bottom gasket, and the inner ring petal component includes a plurality of small arc-shaped components. The plurality of small arc-shaped components are enclosed around the bottom gasket to cooperate with the bottom gasket to form a pressure chamber. In the embodiment of the present application, three arc-shaped components are arranged, and the material can be placed in the pressure chamber formed by the three arc-shaped components to cooperate with the pressure head to extrude and compress the material to form a cake.
[0039] An outer ring locking component is arranged around the inner ring petal component, that is, the outer ring locking component is arranged at the outer position of the inner ring petal component to limit and fix the inner ring petal component. In the embodiment of the present application, the outer ring locking component is sleeved on the periphery of the three arc-shaped components, so that the inner side of the outer ring locking component abuts against the outer side of the three arc-shaped components, so that the arc-shaped components in the inner ring petal component are squeezed against each other, so that the material set in the present application can be specifically limited to form a pressure chamber, wherein a through hole is provided on the outer ring locking component at a position corresponding to the pressure chamber. The setting of the through hole allows the pressure head to extrude the material in the pressure chamber through the outer ring locking component, so that the pressure head can press the material conveniently.
[0040] In the present application, the pressure head can extrude the material through a pressure testing machine, and the extrusion stress is 5-200MPa, and this stress range can extrude the material into a cake.
[0041] Among them, in the embodiment of the present application, the above-mentioned material is mainly coal gangue, weighing 500g, the maximum particle size of the material particles is 5mm, the inner diameter of the pressure chamber is 100mm, the loading speed of the pressure testing machine is 6mm / min, and the loading time range is 120-250s.
[0042] Furthermore, in the embodiment of the present application, the material bed height meets the requirement of being more than 5 times of the feed particle size, and the inner diameter of the pressure chamber meets the requirement of being more than 3 times of the material bed height, so that the influence of the side wall effect on the overall material bed crushing effect can be ignored.
[0043] Under the above device, the embodiment of the present application provides a method for testing the yield performance of a material bed crushed material cake, which can test the compression yield performance of the material cake, such as Figure 7 As shown, the specific test process is:
[0044] Step 1: compressing and loading the material under preset loading stress and loading speed conditions by using an extrusion crushing device to obtain a material cake;
[0045] Step 2: Measure the thickness of the cake and calculate the density of the cake;
[0046] Step 3: Place the cake in a pressure testing machine to perform a compression yield strength test and generate a corresponding stress-strain curve;
[0047] Step 4: Find the yield point in the stress-strain curve and determine the yield strength of the cake.
[0048] The above process is as follows:
[0049] Table 1 Material particle size distribution
[0050] Particle size range (mm) Weight(g) 2.5-5 51.55 1.25-2.5 50.60 0.63-1.25 51.50 0.315-0.63 81.77 0.16-0.315 85.04 0.08-0.16 84.11 0-0.08 95.43
[0051] After the materials are mixed evenly according to the particle grading in Table 1, they are put into an extrusion crushing device, and the device is placed on a pressure testing machine for a material bed ballast crushing test, wherein the preset loading force and loading speed in the above step 1 are both those mentioned above: the loading force range is 5-200MPa, and the preset loading speed is 1-55mm / min, wherein the preset loading speed in the embodiment of the present application is 6mm / min, and the preset loading time range is 120-250s.
[0052] After the loading test, the components of the extrusion and crushing device are removed by a three-jaw puller to obtain a complete cake for the second step, in which the thickness of the cake needs to be measured. The density of the cake is calculated based on the measured thickness, the inner diameter of the pressure chamber and the overall weight of the cake.
[0053] After calculating the density of the cake, the cake is placed on a pressure testing machine for a compression yield strength test and the step three process is performed. The purpose of this process is mainly to avoid interference from other factors.
[0054] In the above step three, a stress strain capturer is provided on the pressure testing machine, and the stress strain capturer can capture the stress and strain change values of the material in the stage of extruding the material to form a cake and the stage of the compression yield strength test of the cake during the test, thereby obtaining corresponding data.
[0055] In the embodiment of the present application, the stress and strain capturer can be captured and tested by a stress and strain tester.
[0056] By performing a compression yield strength test, the yield strength value of the cake can be obtained and the corresponding stress-strain curve can be generated, such as Figure 4As shown in the figure, the yield strength Rp0.2 is an artificially defined conditional yield strength. The conditional yield strength is mainly set because some materials have no obvious yield phenomenon. Usually, the stress when a slight plastic deformation of 0.2% occurs is used as the yield strength. The stage from the origin to the starting point of the elastic section is the compaction process of the particles inside the cake. Because the cake is composed of particles of different particle sizes, the particles are not in close contact with the edges of the particles, and there are gaps inside the cake.
[0057] In step 4, the search for the yield point includes selecting the stress value corresponding to the yield point as the yield strength value when the yield point of the stress-strain curve is obvious;
[0058] When the yield point of the stress-strain curve is not obvious, the point corresponding to the slight plastic deformation is selected to characterize the yield strength value of the cake, that is, the stress at the slight plastic deformation of 0.2% is taken as the yield strength.
[0059] In the embodiment of the present application, further, in order to more effectively detect the yield strength, the pressure testing machine sets the maximum stress value according to a certain gradient, and three sets of repeated tests are performed for each stress value. The maximum deviation between the density of the cakes obtained by the three repeated tests does not exceed 0.01g / cm 3 , as shown in Table 2.
[0060] Table 2 Preset loading stress, cake density and yield strength
[0061] Preset loading stress (MPa) <![CDATA[Cake density (g / cm 3 )]]> Yield strength(MPa) 6.4 1.97 1.802 6.4 1.97 1.701 6.4 1.97 2.011 12.8 2.05 4.624 12.8 2.05 4.545 12.8 2.05 4.570 25.6 2.12 8.688 25.6 2.12 8.494 25.6 2.12 8.978 51 2.21 16.279 51 2.21 15.058 51 2.22 15.917 76.5 2.26 20.321 76.5 2.26 21.017 76.5 2.27 21.003 102 2.33 25.559 102 2.33 24.827 102 2.33 25.041 127.4 2.35 28.576 127.4 2.36 27.338 127.4 2.36 29.013 152.9 2.38 31.120 152.9 2.38 31.111 152.9 2.38 31.512 191.1 2.40 33.298 191.1 2.40 33.504 191.1 2.40 32.614
[0062] The yield strength data obtained from the test in Table 2 and the cake density data are fitted and regressed to generate a fitted regression line. The fitted regression line is shown in the appendix of the manual. Figure 5 , the yield curve of the material in this embodiment is obtained by the fitted regression line:
[0063] y=76.9438x-153.33286,R 2 =0.97798
[0064] Among them, x is the density of the cake, y is the yield strength, R 2 is the degree of fit.
[0065] At the same time, the present application also provides another embodiment. The experimental steps in the other embodiment are the same as those in the previous embodiment, but the preset loading stress is different from the loading stress in the previous embodiment. The specific contents are shown in Table 3 below:
[0066] Table 3 Preset loading stress, cake density and yield strength
[0067] Preset loading stress (MPa) <![CDATA[Cake density (g / cm 3 )]]> Yield strength(MPa) 25.6 2.21 5.273 25.6 2.21 5.103 25.6 2.21 4.973 51 2.30 11.016 51 2.30 12.585 51 2.29 12.615 76.5 2.36 17.451 76.5 2.37 17.823 76.5 2.37 17.714 102 2.40 23.521 102 2.40 23.704 102 2.41 24.769 127.4 2.44 28.538 127.4 2.44 28.108 127.4 2.44 28.731
[0068] In this embodiment, the material is cement raw material (clinker + mixed material) entering the roller silo of the roller press, the material weight is 500g, and the particle gradation is the same as that in the previous embodiment.
[0069] The yield strength data obtained from the test in Table 3 and the cake density data are fitted and regressed to generate a fitted regression line. The fitted regression line is shown in the appendix of the manual. Figure 6 , the yield curve of the material in this embodiment is obtained by the fitted regression line:
[0070] y=101.11417x-219.60256, R2=0.97682
[0071] Where: x is the density of the cake, y is the yield strength, and R2 is the fit.
[0072] The fitting equations of different materials with the same particle size distribution in the two embodiments have different slopes and intercepts, which can characterize the difference in yield properties between the two.
[0073] The analysis method and device of the yield performance of the material are of great significance for the subsequent research on the control of the output of the material cake with appropriate strength by the material bed crushing equipment and the stability of the material bed. It should be pointed out that the material bed ballast crushing device, material cake yield strength test and analysis method used in the present invention are not limited to the materials and their particle gradation distribution used in the embodiments. Any similar device and analysis method are within the protection scope of the present invention.
[0074] The above embodiments are only used to illustrate the technical method of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical method of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical method of the present invention.
Claims
1. A method for testing the yield performance of a material bed crushed cake, characterized in that: include: Step 1: compressing and loading the material under preset loading stress and loading speed conditions by using an extrusion crushing device to obtain a material cake; Step 2: Measure the thickness of the cake and calculate the density of the cake; Step 3: Place the cake in a pressure testing machine to perform a compression yield strength test and generate a corresponding stress-strain curve; Step 4: Find the yield point in the stress-strain curve and determine the yield strength of the cake.
2. The yield performance testing method of a material bed crushing cake according to claim 1, characterized in that: In the step 1, the preset loading stress range is 5-200 MPa, and the preset loading speed is 1-55 mm / min.
3. The yield performance testing method of a material bed crushing cake according to claim 1, characterized in that: In the step three, the pressure testing machine includes a stress-strain capturer, which captures the stress-strain variation values in the stage of extruding the material to form a cake and the stage of performing a compression yield strength test on the cake.
4. The yield performance testing method of a material bed crushing cake according to claim 1, characterized in that: In step 4, the yield point finding and judging process includes: When the yield point of the stress-strain curve is obvious, the stress value corresponding to the yield point is selected as the yield strength value; When the yield point of the stress-strain curve is not obvious, the point corresponding to the slight plastic deformation is selected to characterize the yield strength value of the cake.
5. The yield performance testing method of a material bed crushing cake according to claim 1, characterized in that: The method also includes repeating steps one to four under different preset loading stress conditions, recording the cake thickness and its compressive yield strength obtained in each test after the cake is formed, calculating the cake density based on the cake thickness, and performing linear fitting on the yield strength and density.
6. A method for testing the yield performance of a material bed crushed cake according to claim 5, characterized in that: Different loading stress settings have stress gradient values, and the maximum stress value is taken within each stress gradient value range, and each stress value is made into multiple groups, each group including steps one to four.
7. An extrusion crushing device, used to perform the yield performance test method of a material bed crushing cake according to claim 1, characterized in that: The invention comprises a tray, wherein a bottom gasket is arranged on the tray, an inner ring petal component and an outer ring locking component are arranged around the bottom gasket, the inner ring petal component is located inside the outer ring locking component, so that the outer ring locking component squeezes and limits the inner ring petal component, the inner ring petal component cooperates with the bottom gasket to form a pressure cavity, and a pressure head is arranged on the top of the pressure cavity.
8. The extrusion crushing device according to claim 7, characterized in that: The pressure head is connected to the pressure testing machine so that the pressure testing machine pushes the pressure head to squeeze the pressure chamber.