A real-time detection method for the flowability of mixed material in a mixer

Abstract

The application discloses a kind of detection methods of the flowability of mixture in mixer, comprising the following steps: (a) measure the number of blades n in mixer before stirring, the length L of blade support arm and the equivalent projection area S of each blade i , the calculation method of the equivalent projection area is wherein the area of blade S i ; θ i It is the included angle between blade S i And blade support arm L;(b) temporarily install a torque sensor on the mixer, the torque T0 of mixer can be obtained by the torque sensor, measure the current I0 in mixer at this time, so as to obtain the proportionality coefficient of torque and current, unload the torque sensor after obtaining proportionality coefficient;(c) start mixer and measure the real-time current I of mixer, obtain the real-time resistance coefficient of mixture in mixer by resistance coefficient formula, so as to be used to evaluate the flowability of real-time stirring of material in whole-pot mixer.

Description

Technical Field

[0001] This invention relates to the technical field of evaluating the flowability of mixtures in a mixer, and particularly to a real-time detection method for the flowability of mixtures in a mixer. Background Technology

[0002] The flowability of a mixture is both an important indicator of the mixture itself and an evaluation indicator of its uniformity. Currently, several patents have been published regarding the flowability of mixtures. For example, Chinese patent application (Evaluation Device for Flowability of Glass Mixtures and Raw Materials CN202322153421.5) discloses a device for evaluating the flowability of glass mixtures and raw materials, which detects the diffusion level lines that molten glass can reach after being poured onto a grading pan, thereby evaluating its flowability. Chinese patent application (A Flowability Testing Device and Method for Permeable Concrete CN202211168389.1) proposes a flowability testing device for permeable concrete, characterizing the flowability of permeable concrete based on the distribution differences of its cementitious materials. Chinese patent application (A Flowability Method and Testing Equipment for Cement Slurry CN202311156492.9) discloses a flowability testing device, using the weight ratio of the slurry before and after reversal as data characterizing the slurry's flowability. It is well known that material mixing must be carried out using a mixer to achieve uniform mixing. The detection methods corresponding to the above patent applications are difficult to integrate into the mixer for real-time online flowability testing. Therefore, the mixture must be removed from the mixer and placed into the proposed specific detection device for separate flowability testing. Summary of the Invention

[0003] The technical problem to be solved by this invention is how to detect the flowability of the mixture in the mixer in real time.

[0004] The present invention adopts the following technical solution: a method for real-time detection of the flowability of a mixture in a mixer, comprising the following steps:

[0005] (a) Measure the number of blades n, the length L of the blade support arm, and the equivalent projected area S of each blade inside the mixer before mixing. i The equivalent projected area is calculated as follows: in For blade S i The area; θ i For blade S i The angle between the blade support arm L and the blade support arm L;

[0006] (b) A torque sensor is temporarily installed on the mixer to obtain the torque T0 of the mixer. The current I0 inside the mixer at this time is measured, thereby obtaining the torque-to-current ratio coefficient. After obtaining the proportional coefficient, unload the torque sensor;

[0007] (c) Start the mixer and measure the real-time current I of the mixer, using the resistance coefficient formula. The real-time resistance coefficient of the mixture inside the mixer is obtained, which can then be used to evaluate the flowability of the material during real-time mixing within the entire batch of the mixer.

[0008] Preferably, the method further includes the following steps:

[0009] (d) Obtain the curve of the flowability of the mixture in the mixer as a function of time by detecting the resistance coefficient in step (c) at equal time intervals.

[0010] Preferably, the method further includes the following steps:

[0011] (e) When the resistance coefficient in the curve in step (d) tends to be fixed over time, the mixing is complete and the mixer is stopped.

[0012] The present invention has the following beneficial effects: The fluidity evaluation index for mixed materials proposed in this invention can comprehensively assess the changes in fluidity and uniformity of all mixed materials in a mixer during the mixing process. Typically, after multiple materials are mixed uniformly in a mixer, the above-mentioned fluidity evaluation index will tend to a stable value. Therefore, a dynamic monitoring and evaluation method is needed to assess the mixing uniformity of different mixed materials. Simultaneously, its final stable value can also form a final evaluation of the overall fluidity of the mixed materials in the batch. Therefore, the above-mentioned fluidity calculation method is very suitable for integration into the actual working process of a mixer and does not require additional detection devices; thus, it is low in cost and highly practical. Attached Figure Description

[0013] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0014] Figure 1 This is a simplified diagram for calculating the equivalent surface area of ​​the mixer blades according to the present invention;

[0015] Figure 2 This is a simplified diagram showing the forces acting on the main shaft and blades of the mixer of the present invention. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to represent selected embodiments of the invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0018] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0019] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0020] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0021] Example

[0022] The following are merely preferred embodiments of the present invention. The scope of protection of the present invention is not limited to the following embodiments. All technical solutions that fall within the scope of the present invention are within the scope of protection of the present invention.

[0023] This invention provides a method for detecting the flowability of a mixture in a mixer, comprising the following steps:

[0024] (a) Measure the number of blades n, the length L of the blade support arm, and the equivalent projected area S of each blade inside the mixer before mixing. i The equivalent projected area is calculated as follows: in For blade S i The area; θ i For blade S i The angle between the blade support arm L and the blade support arm L;

[0025] (b) A torque sensor is temporarily installed on the mixer to obtain the torque T0 of the mixer. The current I0 inside the mixer at this time is measured, thereby obtaining the torque-to-current ratio coefficient. After obtaining the proportional coefficient, unload the torque sensor;

[0026] (c) Start the mixer and measure the real-time current I of the mixer, using the resistance coefficient formula. The real-time resistance coefficient of the mixture inside the mixer is obtained, which can then be used to evaluate the flowability of the material during real-time mixing within the entire batch of the mixer.

[0027] The formula for the drag coefficient is obtained as follows: as per the appendix to the instruction manual. Figure 1 The multiple blades inside the mixer rotate with the main shaft, thereby achieving mixing of the material. Blade S... i The projected area along the opposite direction of the instantaneous velocity v is S. i ', where the equivalent projection surface S i The calculation method for ' is as follows:

[0028]

[0029] In equation (1), The blade is S i The area; θ i For blade S i With blade support arm L i The included angle between them (referred to as blade tilt angle).

[0030] In the projected area S i The resistance on the blade S is the resistance of the material being stirred. i The resulting resistance. Here, we assume this resistance to be F. i Therefore, the following liquidity evaluation indicators are proposed:

[0031]

[0032] In equation (2), n is the number of leaves. This represents the sum of the equivalent projected areas of all blades. This represents the total resistance generated by all the blades. C is the drag coefficient, the magnitude of which characterizes the fluidity of the mixed materials.

[0033] Typically, to standardize and reduce costs, the size and installation method of mixer blades are consistent. Therefore, each blade S i Size and area Blade tilt angle θ i Blade support arm L i The size of each is a constant, and the corresponding projected area is S. i ' is a constant. Therefore, equation (3) can be simplified to:

[0034]

[0035] Due to the structural parameters θ of the mixer blades i With S i It is known, therefore, S i It can be calculated directly using equation (1).

[0036] Reference manual attached Figure 2 All blades S i The corresponding resistance F i The generated torque is balanced with the torque T, therefore, the following relationship holds:

[0037]

[0038] As mentioned above, L i This is a constant value, meaning that the distance between each blade and the center of rotation of the main shaft is also the same. Let's assume it to be L. i=L. Further, we can obtain:

[0039]

[0040] In equation (5), n is the number of leaves. Combining equations (3) and (5), we can obtain:

[0041]

[0042] In actual production, the drive current I of the mixer spindle can be directly detected, and it is proportional to the torque T, as shown in equation (7):

[0043] T=k*I(7)

[0044] In equation (7), k is the proportionality coefficient. Typically, a torque sensor is temporarily installed on the mixer, and the torque T of the mixer's main shaft can be obtained through testing. Then, the proportionality coefficient k can be calculated by combining the measured current I.

[0045] Therefore, combining equations (1), (6) and (7), the drag coefficient C can be calculated as follows:

[0046]

[0047] In equation (8), the proportionality coefficient can be determined in advance through experiments. Therefore, in the actual production process of the mixer, the resistance coefficient C can be quickly calculated by detecting the current I and combining it with equation (8), which can then be used to evaluate the flowability of the material being stirred in real time within the entire mixer.

[0048] The real-time resistance coefficient C can usually be obtained by adding the following steps: (e) detecting the resistance coefficient in step (d) at equal time intervals to obtain a curve showing the flowability of the mixture within the mixer over time; and (e) when the resistance coefficient in the curve of step (d) tends to stabilize over time, mixing is complete, and the mixer is stopped. This further evaluates the mixer's performance on different mixtures and its final stable value, which also forms the final evaluation of the overall flowability of the material after uniform mixing.

[0049] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A method for real-time detection of the flowability of a mixed material stream in a blender, characterized by, comprising the steps of: (a) measuring the number of blades n, the length of the blade support arm L and the equivalent projected area S of each blade in the blender before the blender is stirred i , the equivalent projected area is calculated in the following way where is the area of the blade S i ; θ i is the angle between the blade S i and the blade support arm L; (b) temporarily installing a torque sensor on the blender, which torque sensor is capable of providing a torque T0 of the blender, and measuring the current I0 in the blender at that time, thereby obtaining a proportionality factor between torque and current after obtaining the proportionality factor, removing the torque sensor; (c) start the mixer and measure the real-time current I of the mixer, and obtain the real-time resistance coefficient of the mixed materials in the mixer by the resistance coefficient formula the real-time resistance coefficient of the mixed materials in the mixer, so as to evaluate the real-time stirring fluidity of the materials in the whole mixer. (d) detecting the resistance coefficient in step (c) at intervals to obtain a curve of the flowability of the mixed material in the mixer with time; (e) when the resistance coefficient in the curve in step (d) tends to be fixed with time, the mixing is completed, and the mixer is stopped.

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