A method for detecting the wear amount of a mixer blade in real time

Abstract

The application discloses a method for real-time detecting the wear of the blade of a mixer, which is characterized by the following steps: (a) measuring the number of the blades in the mixer before the mixer is stirred, determining the height that the material to be added into the mixer can reach, obtaining the relative sliding linear distance of the material after the stirring blade rotates one circle through the height, determining the blade material, obtaining the wear coefficient K and the material hardness H of the blade according to the blade material, the length L of the blade supporting arm and the area A of the i-th blade i i , θ i is the included angle between the blade i and the blade supporting arm L; (b) temporarily installing a torque sensor on the mixer, obtaining the torque T0 of the mixer through the torque sensor, measuring the current I0 in the mixer at the moment, thereby obtaining the proportional coefficient of the torque and the current, and removing the torque sensor after the proportional coefficient is obtained; (c) starting the mixer and measuring the real-time current I of the mixer, and obtaining the wear depth of the blade in the mixer through the wear depth formula of the blade surface.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of evaluating the wear of the blades in a mixer, and in particular to a method for real-time detection of the wear of the blades in a mixer. BACKGROUND

[0002] During the operation of the mixer, the blades rotate with the main shaft and stir the material. However, after long-term use, the blades will inevitably be worn, which will affect the service life and strength of the blades and ultimately affect the service life of the mixer. However, there are difficulties in evaluating the wear of the blades. Usually, the mixer needs to be shut down, and then the blades are disassembled, and then the thickness difference before and after the wear of the blades is measured to determine the wear. This method has the following disadvantages: 1) During the long-term operation of the blades, some material is permanently adhered to the surface of the blades, which is not easy to remove and affects the accuracy of the thickness measurement. 2) It is inconvenient to disassemble, and it is difficult to implement in actual customer use. 3) Since it needs to be disassembled to be measured, real-time monitoring during the operation of the mixer cannot be achieved. Therefore, in the current engineering application of the mixer, the wear monitoring of the blades cannot be achieved. SUMMARY

[0003] The technical problem to be solved by the present application is how to real-time detect the wear of the blades in the mixer.

[0004] The present application adopts the following technical scheme: a method for real-time detection of the wear of the blades in a mixer, characterized in that it comprises the following steps:

[0005] (a) Measure the number n of blades in the mixer before stirring, determine the height that the material to be added into the mixer can reach, and obtain the relative sliding straight line distance S of the material after one revolution of the stirring blades through the height i * Determine the blade material, obtain the wear coefficient K and the material hardness H of the blade according to the material of the blade, the length L of the blade support arm, and the area A of the i-th blade i i θ i is the angle between the blade i and the blade support arm L;

[0006] (b) Temporarily install a torque sensor on the mixer, which can obtain the torque T0 of the mixer through the torque sensor, measure the current I0 in the mixer at this time, and thus obtain the proportionality coefficient After obtaining the proportionality coefficient, the torque sensor is unloaded;

[0007] (c) Start the mixer and measure the real-time current I of the mixer, and obtain the wear depth formula of the blade surface through the proportionality coefficient Obtaining the wear depth of the blade in the mixer, thereby evaluating the wear amount of the blade in the whole mixer.

[0008] Preferably, the method further comprises the following step: (d) obtaining the wear amount of the blade surface in the mixer over time by detecting the wear depth of the blade surface in step (c) at equal intervals.

[0009] Preferably, the method further comprises the following step: (e) replacing the blade or the stirring head when the wear depth of the blade surface is detected to be 1 / 4 of the thickness of the blade.

[0010] The present application has the following advantages: the blade wear prediction method provided by the present application considers the influence of the driving current of the main shaft and the real-time working condition of the mixer. Therefore, the method is in line with the engineering practice. Meanwhile, the method does not need to disassemble the blade, is very suitable for real-time monitoring during the working process of the mixer, and has low cost, high speed and strong practicability. BRIEF DESCRIPTION OF DRAWINGS

[0011] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the embodiments will be briefly introduced as follows. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be considered as a limitation to the scope. For those skilled in the art, other related drawings can also be obtained without creative labor.

[0012] Figure 1 A calculation diagram of the resistance generated by the equivalent projection of the blade of the mixer of the present application;

[0013] Figure 2 A force diagram of the relationship between the normal force and the resistance of the blade of the mixer of the present application;

[0014] Figure 3 A calculation diagram of the straight-line distance of the effective relative sliding of the blade of the mixer of the present application;

[0015] Figure 4 A force diagram of the main shaft and the blade of the mixer of the present application. DETAILED DESCRIPTION

[0016] In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative effort are within the scope of protection of the present application. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0017] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0018] In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features referred to. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "plurality" is two or more, unless otherwise explicitly specified and limited.

[0019] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection", "fixing" and the like should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral; it can be mechanical connection, or electrical connection; it can be direct connection, or indirect connection through intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For a person of ordinary skill in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0020] In the present application, unless otherwise explicitly specified and limited, the first feature is "on" or "under" the second feature can include that the first and second features are in direct contact, or can include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the first feature is "on", "above" and "over" the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the first feature is higher in horizontal height than the second feature. The first feature is "under", "below" and "underneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or only indicates that the first feature is lower in horizontal height than the second feature.

[0021] Embodiment

[0022] The following is only a preferred embodiment of the present application, and the protection scope of the present application is not limited to the following examples only, and any technical solution falling within the concept of the present application belongs to the protection scope of the present application.

[0023] The present application provides a method for real-time detection of the wear amount of a stirring blade, comprising the following steps:

[0024] (a) measuring the number n of blades in the stirring machine before stirring, determining the height that the material to be added into the stirring machine can reach, and obtaining the relative sliding linear distance of the material after one rotation of the stirring blade through the height determining the blade material, obtaining the wear coefficient K and the material hardness H of the blade according to the material of the blade, the length L of the blade support arm, and the area A of the i-th blade i i , θ i is the included angle between the blade i and the blade support arm L;

[0025] (b) temporarily installing a torque sensor on the stirring machine, obtaining the torque T0 of the stirring machine through the torque sensor, measuring the current I0 in the stirring machine at this time, and thereby obtaining the proportional coefficient of torque and current after obtaining the proportional coefficient, unloading the torque sensor;

[0026] (c) starting the stirring machine and measuring the real-time current I of the stirring machine, and obtaining the wear depth of the blade in the stirring machine through the wear depth formula of the blade surface obtaining the wear depth of the blade in the stirring machine, thereby evaluating the wear amount of the stirring blade in the whole stirring machine.

[0027] The wear depth formula of the blade surface is obtained as follows: as shown in the accompanying drawings Figure 1 The rotation speed of the main shaft of the stirring machine is ω. The area of the blade i is A i . θ i is the included angle between the blade i and the blade support arm L i , which is referred to as the blade inclination angle. The equivalent projection plane corresponding to the blade i is Ai ', A i '=A i cosθ i Projection plane A i Resistance F on ' i This refers to the resistance exerted by the agitated material on the blade i. F i N This refers to the normal force exerted by the material on blade i during the mixing process. (See attached instruction manual.) Figure 2 The figure shows the relationship between friction and resistance in mixer blade i. We can obtain:

[0028] F i N =F i ' / cosθ i (1)

[0029] The equivalent projection surface A i ' is the projected area along the opposite direction of the instantaneous velocity u. The blade velocity u is:

[0030] u=ω×L i (2)

[0031] Currently, the Archard model is the most widely used in wear calculation applications. Based on this model, the relationship between the wear volume of blade i and the load, sliding distance, and hardness can be established, as shown below:

[0032]

[0033] In the formula, V i Let be the wear volume of blade i, K be the wear coefficient, and H be the material hardness. This is the linear distance of the relative sliding between the blade and the material.

[0034] Since the blades inside the mixer bear force on their entire surface, assuming the wear depth is the same at all locations on the blade surface, then:

[0035] V i =h i ×A i (4)

[0036] Combining equations (3) and (4), we can obtain:

[0037]

[0038] Where A i The blade area can be obtained through measurement. K is the wear coefficient, and H is the material hardness, which can be obtained from a handbook based on material properties. Additionally, the linear distance of relative sliding of the stirring blade after one revolution is also considered. The blade motion track is a straight line of the material height line, thus, as long as the structure of the mixer is known, The relative sliding distance of the blade can be obtained. Referring to the drawing Figure 3 The relative sliding distance of the blade can be obtained. Referring to the drawing The relative sliding distance of the blade can be obtained. Referring to the drawing

[0039] The relative sliding distance of the blade can be obtained. Referring to the drawing Figure 4 The relative sliding distance of the blade can be obtained. Referring to the drawing

[0040]

[0041] In formula (6), n is the number of the blades.

[0042] Since the sizes of the blades are the same and the distances of the blades from the rotation center of the main shaft are also the same (here, it is assumed that L i =L), it is assumed that the force conditions of the blades are approximately the same, i.e.:

[0043] F1'=F2'=...=F n '. Further, it can be obtained that:

[0044]

[0045] In formula (7), n is the number of the blades.

[0046] In actual production, the driving current I of the main shaft of the mixer can be directly detected, and it is in a proportional relationship with the torque T, i.e.:

[0047] T=k×I(8)

[0048] In formula (8), k is a proportional coefficient. Generally, a torque sensor is temporarily installed on the mixer, and the torque T of the main shaft of the mixer can be obtained through test, and then the proportional coefficient k can be calculated by combining the current I measured in the test.

[0049] Therefore, by combining formula (1), (7) and formula (8), the following can be obtained:

[0050]

[0051] Finally, formula (9) is brought into formula (5), and the following can be obtained:

[0052]

[0053] As mentioned above, the size of all the blades are the same, the installation way is the same, and the wear depth of each blade is approximately equal, therefore, the wear depth of blade i calculated by formula (10) can be approximately equal to the average wear depth of each blade.

[0054] Generally, the real-time wear depth of the blade can also be obtained by adding the following steps: (d) detecting the wear depth of the blade surface in step (c) at the same interval of time to obtain the curve of the wear amount of the blade surface in the mixer changing with time; (e) when the wear depth of the blade surface is detected to be 1 / 4 of the thickness of the blade, the mixer blade or the stirring head is replaced. The blade wear of the mixer for different mixed materials and the timing of replacing the blade or the stirring head are further evaluated.

[0055] The above embodiments are only for illustrating the technical concept and characteristics of the present application, and the purpose is to enable those skilled in the art to understand the content of the present application and to implement it, and cannot limit the protection scope of the present application. Any equivalent changes or modifications made according to the spirit and essence of the present application shall be covered within the protection scope of the present application.

Claims

1. A method of detecting the amount of wear of a blade of a mixer in real time, characterized in that, comprising the steps of: (a) measuring the number of blades n in the blender before stirring, determining the height of the material to be added into the blender, and obtaining the relative sliding linear distance of the material after one rotation of the stirring blade through the height determining the blade material, obtaining the wear coefficient K of the blade according to the material of the blade and the material hardness H, the length L of the blade support arm, and the area A of the i-th blade i i , θ i is the angle between the blade i and the blade support arm L; (b) temporarily installing a torque sensor on the mixer, which torque sensor enables the torque T0 of the mixer to be obtained, and measuring the current I0 in the mixer at that time, thereby obtaining a proportionality factor between torque and current after the proportionality factor has been obtained, the torque sensor is removed (c) start the mixer and measure the real-time current I of the mixer, and the wear depth of the blade surface is calculated by the formula The wear depth of the blade in the mixer is obtained, thereby evaluating the wear amount of the mixer blade in the entire pot mixer; (d) detecting the wear depth of the blade surface in step (c) at intervals to obtain a curve of the wear amount of the blade surface in the mixer with respect to time; (e) when the wear depth of the blade surface is detected to be 1 / 4 of the thickness of the blade, replacing the mixer blade or the mixing head.

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