CN116087034A

CN116087034A - Device and method for rheological mechanical testing of filling slurry containing large-particle gangue

Info

Publication number: CN116087034A
Application number: CN202211477716.1A
Authority: CN
Inventors: 薛东杰; 张辽; 刘殷彤; 潘阮航; 贾震; 段晓博; 程建超; 王路军; 任伟光; 周宏伟
Original assignee: China University of Mining and Technology Beijing CUMTB
Current assignee: China University of Mining and Technology Beijing CUMTB
Priority date: 2022-11-23
Filing date: 2022-11-23
Publication date: 2023-05-09

Abstract

The invention discloses an experimental device and a measuring method for testing rheological characteristic curves of paste filling slurry containing large-particle gangue. The torque sensor is connected with the motor, the stirring blade and the rotor through the coupler, the controller PLC is connected with the motor and the computer, and the torque sensor is connected with the computer. The invention can more accurately measure the rheological property of the filling slurry containing the large-particle gangue, and has the advantages of continuous measurement of rotation speed-torque variation, automatic data recording, high degree of automation, direct acquisition of shear deformation rate-shear stress curve, simple operation and high precision.

Description

Device and method for rheological mechanical testing of filling slurry containing large-particle gangue

Technical Field

The invention relates to the technical field of filling mining equipment, in particular to a device and a method for testing rheological mechanical characteristic curves of filling slurry consisting of large-particle gangue or tailings, cement and fly ash.

Background

In the research of filling mining slurry, the rheological property of the slurry, namely a shear deformation rate-shear stress curve, is an important basic parameter for slurry pipeline transportation and filler formation, and accurate measurement of the rheological parameter of the slurry has important guiding significance for the research of filling mining and engineering practice. The current rheology measurement methods mainly comprise an extrusion type rheometer and a rotary viscometer.

The extrusion rheometer is an experimental device and method mainly used for measuring the melt flow rate or rheological property of high polymer. The structure and measurement principle are that the vertically installed charging barrel is provided with 3 longitudinal holes, one is inserted with a thermometer, the other is provided with a sample, the bottom of the other is provided with an extrusion motion piston with a certain diameter, under the action of a specified static load, the melt of the sample is extruded from the longitudinal holes, and the extrusion quantity after a certain time is measured, so that the shear rate and viscosity are calculated. The method is suitable for fluid with strong plasticity and is not suitable for rheological property test of filling slurry.

Rotational viscometers are capable of rapidly measuring viscosity in the rheological properties of a material by producing a simple tangential motion through relative displacement of two rotating concentric cylinders. Its advantages are stable trimming speed, less test sample, and high precision and chemical synthesis. In a multiphase system, if the width of the dispersed phase particles is close to the distance between the two cylinders, the deviation is larger; and the distance between the cylinders is usually between 0.2 and 2mm, and the large gangue particles contained in the filling slurry used in filling mining are usually 10 to 20mm, so that the flow characteristics cannot be measured by using a rotational viscometer.

Disclosure of Invention

In order to solve the technical problems, the invention provides an experimental device and a testing method for efficiently, automatically and accurately measuring rheological mechanical properties of filling slurry containing large-particle gangue. The measuring device and the measuring method can be applied to rheological test of gangue slurry and rheological test of tailing slurry.

The technical scheme for solving the problems is as follows: the device comprises a vertical experimental device bracket, a stirring power system servo torque integrated motor, a power system controller PLC, a high-precision dynamic torque sensor, a stirring rotor, a blade, a power system coupler, a gangue paste-like filling paste cylindrical container, a sensor data transmission connector and an experimental device shell. The motor, the torque sensor, the stirring rotor and the blades are respectively positioned at the uppermost layer, the middle layer and the bottom layer of the experimental support. The torque sensor is connected with the motor, the stirring blade and the rotor through the coupler, the controller PLC is connected with the motor and the computer, and the torque sensor is connected with the computer.

The test is based on an experimental device containing rheological properties of large-particle gangue filling slurry, and the test principle is as follows: the adopted precise moment instrument can detect the speed and the moment, and the rheological characteristic of the slurry can be calculated by detecting the moment value of the stirring center of the stirring blade at different speeds. The core of the rheometer is a stirring blade and a stirring cylinder.

The test is based on an experimental device containing rheological properties of large-particle gangue filling slurry, a power system is provided by a servo torque integrated motor controlled by a PLC, the PLC controls the motor to drive a stirring blade to move at a variable rotating speed according to a given function, a high-precision torque sensor is used for continuously reading the rotating speed and the torque value, and a signal wire is used for transmitting data to a computer for post-treatment.

The invention has the beneficial effects that: the invention can more accurately measure the rheological property of the filling slurry containing the large-particle gangue, and has the advantages of continuous measurement of rotation speed-torque variation, automatic data recording, high degree of automation, direct acquisition of shear deformation rate-shear stress curve, simple operation and high precision.

Drawings

FIG. 1 is a schematic diagram of a novel rheometer structure according to the invention

FIG. 2 is a schematic view of a stirring blade according to the present invention

FIG. 3 is a schematic diagram of the novel rheometer test principle of the present invention

FIG. 4 is a torque curve obtained by a test example of a filler slurry according to the present invention

FIG. 5 is a graph showing the rotational speed obtained by a test example of a filler slurry according to the present invention

FIG. 6 is a graph of rheological properties calculated for a test example of a filler slurry according to the invention

Detailed Description

The invention is further described below with reference to the drawings and examples.

Referring to fig. 1, an experimental device for testing rheological characteristic curves of paste filling slurry containing large-particle gangue comprises a vertical experimental device bracket 6, a stirring power system servo torque integrated motor 1, a power system controller PLC2, a high-precision dynamic torque sensor 4, a stirring rotor and blades 7, a power system coupler 5, a gangue paste filling slurry cylindrical container 8, a sensor data transmission connector 3 and a lifting experiment table 10.

The motion system firstly regulates and controls the rotation speed change function to the control PLC2 by a computer, and then the PLC2 outputs 100kHz high-frequency pulse to control the servo torque motor to output corresponding rotation speed. Is connected to the same rotation shaft with the high-precision torque sensor 4 and the stirring blade 7 through a coupling 5.

The experimental support 6 is divided into 3 layers, namely an upper layer, a middle layer and a bottom layer. The upper layer is used for fixing the controller PLC2 and the servo torque integrated motor 1, the middle layer is used for fixing the torque sensor 4, and the lower layer is used for fixing the lifting experiment table 9 and the installation cylinder slurry container 8.

The controller PLC2 links the servo torque integrated motor 1 and the computer at the same time, and regulates and controls the rotating speed change function through the computer and controls the servo motor.

The torque sensor 4 is connected with a computer through a data interface 3, and data is transmitted to the computer through the data interface 3 during testing.

In fig. 2, which is a stirring blade, consists of four rectangular blades perpendicular to each other and a link lever 11, and in the test, the blades are rotated in a cylindrical slurry vessel to form a circular velocity gradient distribution, and torque values on the blades are transmitted to the link lever 11 to be measured by a torque sensor 4.

Fig. 3 is a schematic diagram of the stirring blade 7 and the circular stirring cylinder 8 during the test. The radius of the blade edge is R ₁ The rotation speed is omega. In the test, the rotation speed of the slurry at any point in the cylinder is omega, and at the edge of the blade, the rotation speed of the slurry is omega _R1 About equal to the rotational speed of the blades. And the slurry speed omega at any point dr in the barrel is ω+dω. In the rheometer test process, the rotating speed of the slurry, which is close to the inner wall of the stirring cylinder, is 0. The linear velocity of the blade edge is

The linear speed of the edge of the stirring cylinder is +.>

Wherein the mixing drum edge is slip free and therefore has a velocity of zero. The shear deformation rate can be expressed as: />

Let R ₁ ＝kR ₂ The boundary condition may be expressed as:

the velocity profile between the blade and the stirring drum wall can be obtained:

bringing the velocity profile, equation 3, into shear deformation rate equation 1, yields a shear rate of:

wherein: n is the flow index, for a charge slurry fluid, where n is 1, then equation 4 can be reduced to:

in the test process, a proper amount of prepared filling slurry is fixed on a lifting experiment table 9, the height of the lifting experiment table is adjusted to a proper position through an adjusting knob 10, and the upper edge of the stirring blade is immersed below the slurry liquid level by 2cm, so that the height is generally considered to be proper to adjust. In the test, the rotational speed and torque values of the stirring rotor are continuously measured and transmitted to a computer for analysis through the data interface 3.

Taking gangue filling slurry as an example, the rheological property test and calculation method comprises the following steps:

as shown in fig. 4-5, for the torque and rotation speed variation value obtained during the testing process of the slurry, the offset value during the testing process of filtering and noise reduction is reduced by using the LOWESS noise reduction algorithm, so as to reduce accidental errors. The sensed torque value is M, and the rotating speed value is n; the height of the blade is h, and the radius is R ₁ The shear stress calculation formula is:

the shear rate is calculated according to equation 5:

as shown in fig. 6, a rheological characteristic curve of the gangue filling slurry, namely a graph of "shear rate-shear stress", is calculated.

Claims

1. A rheological mechanical testing device and a rheological mechanical testing method for filling slurry containing large-particle gangue are characterized in that: the device comprises a vertical experimental device support, a stirring power system servo torque integrated motor, a power system controller PLC, a high-precision dynamic torque sensor, a stirring rotor and blades, a power system coupler, a gangue paste-like filling slurry cylindrical container, a sensor data transmission connector and an experimental device shell. The torque sensor is connected with the motor, the stirring blade and the rotor through the coupler, the controller PLC is connected with the motor and the computer, and the torque sensor is connected with the computer.

2. The device for rheological mechanical testing of filling slurry containing large-particle gangue according to claim 1, wherein the vertical experimental support is divided into three layers, the first layer is used for assembling a servo torque integrated motor, the second layer is used for assembling a high-precision torque sensor, and the third layer is used for assembling a slurry container, a stirring rotor, a blade and a lifting experiment table.

3. The filling slurry rheological mechanical testing device containing large-particle gangue according to claim 1, wherein the motor is required to support torque servo control, and the control unit PLC outputs high-frequency pulse to control the torque servo motor to drive the stirring blade to rotate according to the changing rotating speed of the designated function. At the same time, the torque output of the motor changes synchronously with the rotational speed and meets the power required for stirring the slurry.

4. The device for rheological mechanical testing of filling slurry containing large-particle gangue of claim 1, wherein the high-precision torque sensor is a dynamic torque sensor. The torque of the rotating shaft can be continuously measured while the test experiment blades are stirred and rotated, and the torque value is transmitted to the computer in real time through the IO interface.

5. The device for rheological mechanical testing of filling slurry containing large-particle gangue according to claim 1, wherein the stirring rotor and the blades are formed by cylindrical stirring and welding of cross-shaped blades. The stirring length meets the adjustment requirement of the distance of the adjusting blade extending into the slurry liquid level. The cross-shaped blades are formed by welding four rectangular thin steel sheets which are perpendicular to each other, deformation of the blades in the slurry stirring process is negligible, and certain rigidity requirements are met.

6. The filling slurry rheology testing device containing large-particle gangue according to claim 1, wherein the slurry container is in a straight cylinder shape, and the diameter of the cylinder and the diameter of the stirring blade meet the calculation method in rheology testing principle.

7. A filling slurry rheology testing device and measurement method based on the large particle gangue comprising filling slurry rheology testing device and measurement method of any one of claims 1-6 comprising the steps of:

(1) Test slurry is prepared according to the experimental requirements, and the fully and uniformly stirred filling slurry is poured into a cylindrical stirring container, and the height of a lifting experiment table is adjusted to enable the upper edge of a stirring blade to be immersed under the slurry liquid surface for 2cm.

(2) The PLC outputs high-frequency pulse to control the servo motor to rotate by giving instructions through the computer. The rotational speed varies according to a given function. And simultaneously, the torque sensor is connected with the computer, and the rotating speed and the torque value measured by the sensor are continuously transmitted to the computer and recorded.

(3) And exporting the measured data from the upper computer software for post-processing, and preprocessing the obtained torque and rotation speed data by adopting a signal noise reduction algorithm.

(4) And selecting a speed change period from the measured data, and calculating to obtain a rheological characteristic curve of the shear deformation rate-shear stress of the filling slurry by adopting an algorithm in a rheological mechanical test principle.