Cutting dust purification coefficient measuring device and measuring method

Abstract

This invention discloses a cutting dust purification coefficient measuring device, comprising a cavity and a control system; a positive pressure air inlet system and a cutting dust feeding system are connected to the cavity air inlet, and a negative pressure air outlet system is connected to the cavity air outlet; the positive pressure air inlet system includes a first axial flow fan, a first filter connected to the first axial flow fan, and the air outlet of the first axial flow fan is connected to the cavity air inlet through a valve group, the valve group including an electric ball valve and a solenoid valve connected in series; the cutting dust feeding system includes a cutting dust storage bin and a screw feeder driven by a motor, and a weighing sensor is installed below the cutting dust storage bin; a three-way pipe is provided between the valve group and the cavity air inlet, and the discharge port of the screw feeder is connected to the three-way pipe; the negative pressure air outlet system includes a second axial flow fan, the air inlet of the second axial flow fan is connected to the cavity air outlet, and a second filter is connected to the air outlet of the second axial flow fan. This invention also discloses a cutting dust purification coefficient measuring method.

Description

Technical Field

[0001] This invention belongs to the technical field of particle characteristics testing, specifically a device and method for measuring the dust purification coefficient of cutting powder. Background Technology

[0002] The prevention and control of particulate pollution is of paramount importance in certain fields, including environment, chemical industry, and nuclear energy. Micron-sized particles easily become suspended within the cavities of equipment and instruments, posing a hazard to both equipment and personnel. Current technologies typically employ forced convection to remove suspended particles from complex cavities where particulate pollutants tend to accumulate and deposit. This involves simultaneously introducing and expelling air from the cavity, fluidizing the suspended particles and allowing them to be expelled with the airflow, thus purifying the cavity. However, existing methods rely solely on constant airflow velocity to remove suspended particles. Due to variations in cavity structure, particle size, and mass, the particle removal rate varies considerably, meaning that under certain operating conditions, effective particle removal is not achieved. Summary of the Invention

[0003] In view of this, the purpose of the present invention is to provide a cutting dust purification coefficient measuring device and method, which can obtain the solid particle purification coefficient under different wind speeds and frequencies under specific cavity structures and cutting dust volume and weight conditions, and thus obtain the wind speed and frequency for obtaining the maximum purification coefficient.

[0004] To achieve the above objectives, the present invention provides the following technical solution:

[0005] This invention first proposes a cutting dust purification coefficient measuring device, including a cavity and a control system; the cavity is provided with a cavity air inlet and a cavity air outlet; the cavity air inlet is connected to a positive pressure air inlet system and a cutting dust feeding system, and the cavity air outlet is connected to a negative pressure air outlet system;

[0006] The positive pressure air intake system includes a first axial flow fan, with a first filter connected to the air inlet of the first axial flow fan, and the air outlet of the first axial flow fan connected to the cavity air inlet via a valve group. The valve group includes an electric ball valve and a solenoid valve connected in series, with the electric ball valve located between the solenoid valve and the first axial flow fan. The electric ball valve controls the air intake flow rate by adjusting its opening degree, and the solenoid valve adjusts the air intake frequency by opening and closing control.

[0007] The cutting dust feeding system includes a cutting dust storage bin for storing cutting dust and a screw feeder driven by a motor for conveying cutting dust. A weighing sensor is installed below the cutting dust storage bin. A three-way pipe is provided between the valve group and the cavity air inlet, and the discharge port of the screw feeder is connected to the three-way pipe.

[0008] The negative pressure air outlet system includes a second axial flow fan, the air inlet of the second axial flow fan is connected to the air outlet of the cavity, and a second filter is connected to the air outlet of the second axial flow fan;

[0009] The control system is electrically connected to the first axial flow fan, the second axial flow fan, the electric ball valve, the solenoid valve, the motor, and the weighing sensor, respectively, and:

[0010] The control system controls the intake air speed by controlling the rotational speeds of the first axial flow fan and the second axial flow fan, respectively.

[0011] The control system adjusts the air intake flow by controlling the opening degree of the electric ball valve;

[0012] The control system controls the opening and closing of the solenoid valve to change the intake airflow into a pulsating airflow and adjust the frequency of the pulsating airflow.

[0013] The control system controls the speed and start / stop of the motor based on the weight data collected in real time by the weighing sensor, so as to control the feed flow rate and total feed weight of the cutting dust.

[0014] Furthermore, at least two axial flow fans are connected in series.

[0015] Furthermore, a first particle concentration sensor for detecting the concentration of cutting dust is provided between the first filter and the first axial flow fan; a second particle concentration sensor is provided at the air outlet of the second filter; and a third particle concentration sensor for detecting the concentration of cutting dust is provided inside the cavity.

[0016] Furthermore, a thermal gas mass flow meter is installed between the three-way pipe and the valve group. The thermal gas mass flow meter is connected to the control system to monitor the inlet air flow and inlet air velocity in real time.

[0017] Furthermore, the cavity is made of a transparent material.

[0018] Furthermore, it also includes an observation system, which includes a data acquisition system and two high-speed cameras. The two high-speed cameras observe the movement trajectory and collision-deposition behavior of the cutting dust flow in the cavity from two mutually perpendicular directions.

[0019] Furthermore, the bottom of the cavity is covered with tin foil for collecting deposited cutting dust.

[0020] Furthermore, a gas differential pressure gauge is provided inside the cavity for detecting the pressure difference between the cavity air inlet and the cavity air outlet.

[0021] This invention also proposes a method for measuring the dust purification coefficient of cutting materials, comprising the following steps:

[0022] Step 1: Determine the optimal pulsation frequency

[0023] 11) Control the speed of the first axial flow fan and the second axial flow fan to the set speed respectively, so that the intake air speed is the set air speed;

[0024] 12) Adjust the opening degree of the electric ball valve to the set opening degree so that the air intake flow rate is the set flow rate;

[0025] 13) Control the solenoid valve to open and close at the set i-th frequency, so as to convert the intake airflow into a pulsating airflow with the set i-th frequency;

[0026] 14) Start the motor to drive the screw feeder to supply cutting dust into the cavity according to the set feed flow rate until the weighing sensor measures that the total weight of the cutting dust fed is equal to the set weight.

[0027] 15) Turn off the motor, the first axial flow fan and the second axial flow fan, weigh the cutting dust deposited in the cavity, and obtain the i-th purification coefficient;

[0028] 16) Plot the i-th point corresponding to the i-th purification coefficient and the i-th frequency on the purification coefficient-frequency coordinate system, and fit the i-th point to the i-th point as a purification coefficient-frequency smooth curve;

[0029] 17) Determine whether the purification coefficient-frequency smoothing curve has a monotonically increasing interval and a monotonically decreasing curve: if yes, then take the frequency corresponding to the peak of the purification coefficient-frequency smoothing curve as the optimal pulsation frequency of the cavity and execute step two; if no, execute step 18).

[0030] 18) Increase the frequency of the pulsating airflow according to the set rule, let i = i + 1, and repeat step 11);

[0031] Step 2: Determine the optimal intake air velocity

[0032] 21) Control the speed of the first axial flow fan and the second axial flow fan respectively, so that the intake air speed is the j-th air speed;

[0033] 22) Adjust the opening of the electric ball valve to the set opening to make the air intake flow rate the j-th air intake flow rate at the j-th wind speed;

[0034] 23) Control the solenoid valve to open and close according to the optimal pulsation frequency, so as to transform the intake airflow into a pulsating airflow with the optimal pulsation frequency;

[0035] 24) Start the motor to drive the screw feeder to supply cutting dust into the cavity according to the set feed flow rate until the weighing sensor measures that the total weight of the cutting dust fed is equal to the set weight.

[0036] 25) Turn off the motor, the first axial flow fan and the second axial flow fan, weigh the cutting dust deposited in the cavity, and obtain the j-th purification coefficient;

[0037] 26) Plot the j-th point corresponding to the j-th purification coefficient and the j-th intake air velocity in the purification coefficient-intake air velocity coordinate system, and fit the first point to the i-th point into a smooth curve of purification coefficient-intake air velocity.

[0038] 27) Determine whether the purification coefficient-intake air velocity smooth curve has a monotonically increasing range and a monotonically decreasing curve: if yes, then take the intake air velocity corresponding to the peak of the purification coefficient-intake air velocity smooth curve as the optimal intake air velocity of the cavity; if no, proceed to step 28).

[0039] 28) Increase the j-th wind speed according to the set rule, let j = j + 1, and repeat step 21).

[0040] This invention also proposes a method for measuring the dust purification coefficient of cutting materials, comprising the following steps:

[0041] S1: Determine the optimal intake air velocity

[0042] S11) Control the speed of the first axial flow fan and the second axial flow fan respectively, so that the intake air speed is the nth air speed;

[0043] S12) Adjust the opening of the electric ball valve to the set opening, so that the air intake flow rate is the nth air intake flow rate at the nth wind speed;

[0044] S13) Control the solenoid valve to open and close at a set frequency, and convert the intake airflow into a pulsating airflow with a set pulsating frequency.

[0045] S14) Start the motor to drive the screw feeder to supply cutting dust into the cavity according to the set feed flow rate until the weighing sensor measures that the total weight of the cutting dust fed is equal to the set weight.

[0046] S15) Turn off the motor, the first axial flow fan and the second axial flow fan, weigh the cutting dust deposited in the cavity, and obtain the j-th purification coefficient;

[0047] S16) Plot the nth point corresponding to the nth purification coefficient and the nth intake air velocity in the purification coefficient-intake air velocity coordinate system, and fit the first point to the nth point into a purification coefficient-intake air velocity smooth curve.

[0048] S17) Determine whether the purification coefficient-intake air speed smooth curve has a monotonically increasing range and a monotonically decreasing curve: if yes, then take the intake air speed corresponding to the peak of the purification coefficient-intake air speed smooth curve as the optimal intake air speed of the cavity; if no, proceed to step S18).

[0049] S18) Increase the nth wind speed according to the set rule, let n = n + 1, and repeat step S11 in a loop.

[0050] Step S2: Determine the optimal pulsation frequency

[0051] S21) Control the speed of the first axial flow fan and the second axial flow fan to the set speed respectively, so that the intake air speed is the optimal intake air speed;

[0052] S22) Adjust the opening of the electric ball valve to the set opening to make the intake flow rate the optimal airflow rate under the optimal intake wind speed;

[0053] S23) Control the solenoid valve to open and close at a set frequency m, so as to convert the intake airflow into a pulsating airflow with a set frequency m.

[0054] S24) Start the motor to drive the screw feeder to supply cutting dust into the cavity according to the set feed flow rate until the weighing sensor measures that the total weight of the cutting dust fed is equal to the set weight.

[0055] S25) Turn off the motor, the first axial flow fan and the second axial flow fan, weigh the cutting dust deposited in the cavity, and obtain the m-th purification coefficient;

[0056] S26) Plot the m-th point corresponding to the m-th purification coefficient and the m-th frequency in the purification coefficient-frequency coordinate system, and fit the points from the 1st point to the m-th point into a purification coefficient-frequency smooth curve;

[0057] S27) Determine whether the purification coefficient-frequency smoothing curve has a monotonically increasing interval and a monotonically decreasing curve: if yes, then take the frequency corresponding to the peak of the purification coefficient-frequency smoothing curve as the optimal pulsation frequency of the cavity and execute step two; if no, execute step S28).

[0058] S28) Increase the frequency of the pulsating airflow according to the set rule, let m = m + 1, and repeat step S21 in a loop.

[0059] The beneficial effects of this invention are as follows:

[0060] The cutting dust purification coefficient measuring device of the present invention, by connecting a positive pressure air inlet system and a negative pressure air outlet system to the air inlet and outlet of the mold cavity respectively, and by controlling the rotational speed of the first axial flow fan and the second axial flow fan respectively using a control system, can control the airflow velocity through the mold cavity. By installing an electric ball valve between the first axial flow fan and the mold cavity, and by controlling the opening of the electric ball valve through the control system, the airflow rate through the mold cavity can be adjusted. By installing a solenoid valve between the electric ball valve and the mold cavity, and by controlling the opening and closing of the solenoid valve according to a set rule through the control system, the pulsation frequency of the airflow through the mold cavity can be controlled. By connecting a cutting dust feeding system to the air inlet of the mold cavity, and by controlling the motor speed, the flow rate of cutting dust driven by the screw feeder can be controlled. A weighing sensor can measure the total amount of cutting dust entering the mold cavity. Thus, the cutting dust purification coefficient of the present invention is... In the measuring device, if the rotational speeds of the first and second axial flow fans are kept constant, the cutting dust in the cavity can be removed using a conventional constant airflow. If the rotational speeds of the first and second axial flow fans are varied according to a set pattern, the cutting dust in the cavity can be removed using an airflow with a speed varying according to a set pattern. By controlling the opening and closing of the solenoid valve, the intake airflow can be converted into a pulsating airflow, and the cutting dust in the cavity can be removed using pulsating airflows of different frequencies. That is, the cutting dust purification coefficient measuring device of the present invention can achieve the technical objective of removing cutting dust in the cavity using different types of airflows. Furthermore, by measuring the mass of the cutting dust deposited in the cavity, the solid particle purification coefficient after each airflow acts on the corresponding cavity can be obtained, thereby obtaining the optimal purification coefficient for different cavities and the airflow speed and frequency corresponding to the optimal purification coefficient. Attached Figure Description

[0061] To make the objectives, technical solutions, and beneficial effects of this invention clearer, the following figures are provided for illustration:

[0062] Figure 1 This is a schematic diagram of an embodiment of the cutting dust purification coefficient measuring device of the present invention.

[0063] Explanation of reference numerals in the attached figures:

[0064] 1-Cavity; 2-Control system; 3-First axial flow fan; 4-First filter; 5-Electric ball valve; 6-Solenoid valve; 7-First particle concentration sensor; 8-Thermal gas mass flow meter; 9-Cutting dust storage bin; 10-Motor; 11-Screw feeder; 12-Second axial flow fan; 13-Second filter; 14-Second particle concentration sensor; 15-Data acquisition system; 16-High-speed camera; 17-Third particle concentration sensor; 18-Gas differential pressure gauge. Detailed Implementation

[0065] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0066] like Figure 1 As shown, the cutting dust purification coefficient measuring device of this embodiment includes a cavity 1 and a control system 2. The cavity 1 is provided with a cavity air inlet and a cavity air outlet; a positive pressure air inlet system and a cutting dust feeding system are connected to the cavity air inlet, and a negative pressure air outlet system is connected to the cavity air outlet.

[0067] The positive pressure air intake system of this embodiment includes a first axial flow fan 3. A first filter 4 is connected to the air inlet of the first axial flow fan 3, and the air outlet of the first axial flow fan 3 is connected to the cavity air inlet through a valve assembly. The first filter 4 has the ability to filter micron-level cutting dust, preventing cutting dust in the air from entering the cavity with the airflow and affecting the measurement results. In a preferred embodiment of this embodiment, at least two first axial flow fans 3 are connected in series. In this embodiment, two first axial flow fans 3 are connected in series. Of course, in some other embodiments, the first axial flow fans 3 can also be set to three or more depending on the actual application scenario. By setting at least two first axial flow fans 3 in series, the intake pressure can be increased and a larger intake flow can be provided compared to a single axial flow fan; compared to a traditional air compressor, a continuous and stable gas supply can be provided. In this embodiment, the valve assembly includes an electric ball valve 5 and a solenoid valve 6 connected in series, and the electric ball valve 5 is located between the solenoid valve 6 and the first axial flow fan 3. The electric ball valve 5 controls the airflow by adjusting its opening degree. Under the same airflow velocity, the larger the opening degree of the electric ball valve 5, the larger the airflow; conversely, the smaller the opening degree of the electric ball valve 5, the smaller the airflow. The solenoid valve 6 adjusts the airflow frequency by controlling its opening and closing, thereby converting the airflow into a pulsating airflow. In this embodiment, a first particle concentration sensor 7 for detecting the concentration of cutting dust is provided between the first filter 4 and the first axial flow fan 3. A thermal gas mass flow meter 8 is provided between the solenoid valve 6 and the cavity 1, and the thermal gas mass flow meter 8 is used to monitor the airflow in real time.

[0068] The cutting dust feeding system of this embodiment includes a cutting dust storage bin 9 for storing cutting dust and a screw feeder 11 driven by a motor 10 for conveying the cutting dust. A weighing sensor is installed below the cutting dust storage bin 9. The cutting dust storage bin 9 stores the solid particles (i.e., cutting dust) required for measurement. The motor 10 drives the screw feeder 11 to rotate, and the cutting dust is continuously fed under the action of the screw feeder 11. By measuring the weight of the cutting dust storage bin 9 in real time by the weighing sensor, the weight of the cutting dust input into the mold cavity 1 can be monitored in real time. A three-way pipe is provided between the valve group and the air inlet of the mold cavity. The outlet of the screw feeder is connected to the three-way pipe. In this way, the cutting dust conveyed by the screw feeder 11 reaches the three-way pipe and is blown into the mold cavity 1 by the air inlet. In this embodiment, a thermal gas mass flow meter 8 is installed between the three-way pipe and the valve group.

[0069] The negative pressure air outlet system of this embodiment includes a second axial flow fan 12. The air inlet of the second axial flow fan 12 is connected to the air outlet of the cavity, and a second filter 13 is connected to the air outlet of the second axial flow fan 12. A second particle concentration sensor 14 is provided at the air outlet of the second filter 13 in this embodiment. Similarly, the second filter 13 has the ability to filter micron-level cutting dust, preventing cutting dust in the cavity 1 from entering the external environment and polluting the environment, and enabling the collection and reuse of cutting dust. The second particle concentration sensor 14 can monitor the concentration of cutting dust in the discharged airflow in real time to determine whether the filtration effect of the second filter 13 meets the requirements.

[0070] The control system in this embodiment is electrically connected to the first axial flow fan 3, the second axial flow fan 12, the electric ball valve 5, the solenoid valve 6, the motor 10, and the weighing sensor. The control system controls the intake air velocity by controlling the rotational speeds of the first axial flow fan 3 and the second axial flow fan 12; it adjusts the intake airflow by controlling the opening of the electric ball valve 5; it changes the intake airflow into a pulsating airflow and adjusts the frequency of the pulsating airflow by controlling the opening and closing of the solenoid valve 6; and it controls the rotational speed and start / stop of the motor 10 based on the weight data collected in real time by the weighing sensor, thereby controlling the feed flow rate and total weight of the cutting dust. The control system monitors the intake air velocity and flow rate in real time using a thermal gas mass flow meter 8.

[0071] In a preferred embodiment of this invention, the cavity 1 is made of a transparent material, which facilitates the observation of the movement of cutting dust within the cavity 1. Specifically, the cavity 1 in this embodiment is made of acrylic sheet. The shape and structure of the cavity 1 are consistent with the actual cavity structure or are a simplified structure that retains the main internal structure of the actual cavity. The size of the cavity 1 can be made proportionally or proportionally reduced relative to the actual cavity to ensure that the measurement conditions and results are consistent with the actual application scenario. The cutting dust purification coefficient measuring device in this embodiment also includes an observation system, which includes a data acquisition system 15 and a high-speed camera 16. In this embodiment, two high-speed cameras 16 are used, and the two high-speed cameras 16 observe the movement trajectory and collision-deposition behavior of the cutting dust flow within the cavity 1 from two mutually perpendicular directions.

[0072] In a preferred embodiment of this example, a third particle concentration sensor 17 is provided inside the cavity 1 to detect the concentration of cutting dust, enabling real-time monitoring of the cutting dust concentration within the cavity 1. In another preferred embodiment, a gas differential pressure gauge 18 is provided inside the cavity 1 to detect the pressure difference between the cavity's air inlet and outlet. Specifically, during the experiment, tin foil can be attached to the bottom of the cavity 1 to collect the deposited cutting dust.

[0073] The following describes in detail the specific implementation of the cutting dust purification coefficient measurement method of the present invention, with reference to the cutting dust purification coefficient measuring device described above in this embodiment.

[0074] According to the applicant's experiments, the maximum purification coefficient of solid particles is mainly affected by wind speed and pulsation frequency. Therefore, in actual measurement, there are two methods. In the first method, under fixed wind speed and flow rate conditions, the optimal pulsation frequency for obtaining the maximum purification coefficient can be measured. Then, using the optimal pulsation frequency, the optimal intake wind speed for obtaining the maximum purification coefficient under different wind speed conditions can be obtained. Thus, the optimal pulsation frequency and optimal intake wind speed for obtaining the maximum purification coefficient for a specific cavity 1 can be obtained. In the second method, under fixed pulsation frequency conditions, the optimal intake wind speed for obtaining the maximum purification coefficient can be measured. Then, using the optimal intake wind speed, the optimal pulsation frequency for obtaining the maximum purification coefficient at different frequencies can be obtained. Thus, the optimal pulsation frequency and optimal intake wind speed for obtaining the maximum purification coefficient for a specific cavity 1 can also be obtained.

[0075] Specifically, the first method for measuring the dust purification coefficient includes the following steps:

[0076] Step 1: Determine the optimal pulsation frequency

[0077] 11) Control the speed of the first axial flow fan 3 and the second axial flow fan 12 to the set speed respectively, so that the intake air speed is the set air speed;

[0078] 12) Adjust the opening degree of the electric ball valve 5 to the set opening degree so that the air intake flow rate is the set flow rate;

[0079] 13) Control the solenoid valve 6 to open and close at the set i-th frequency, so as to convert the intake airflow into a pulsating airflow with the set i-th frequency;

[0080] 14) Start motor 10 to drive screw feeder 11 to supply cutting dust into the cavity according to the set feed flow rate until the weighing sensor measures that the total weight of the cutting dust fed is equal to the set weight.

[0081] 15) Turn off motor 10, first axial flow fan 3 and second axial flow fan 12, weigh the cutting dust deposited in cavity 1, and obtain the i-th purification coefficient;

[0082] 16) Plot the i-th point corresponding to the i-th purification coefficient and the i-th frequency on the purification coefficient-frequency coordinate system, and fit the i-th point to the i-th point as a purification coefficient-frequency smooth curve;

[0083] 17) Determine whether the purification coefficient-frequency smoothing curve has a monotonically increasing interval and a monotonically decreasing curve: if yes, then take the frequency corresponding to the peak of the purification coefficient-frequency smoothing curve as the optimal pulsation frequency of the cavity and execute step two; if no, execute step 18).

[0084] 18) Increase the frequency of the pulsating airflow according to the set rule, let i = i + 1, and repeat step 11).

[0085] This verifies the variation law that the purification coefficient first increases and then decreases with the increase of the pulsation frequency of the intake airflow. Therefore, the pulsation frequency corresponding to the maximum purification coefficient can be obtained by curve fitting.

[0086] Step 2: Determine the optimal intake air velocity

[0087] 21) Control the rotation speed of the first axial flow fan 3 and the second axial flow fan 12 respectively, so that the intake air speed is the j-th air speed;

[0088] 22) Adjust the opening of the electric ball valve 5 to the set opening, so that the air intake flow rate is the j-th air intake flow rate at the j-th wind speed;

[0089] 23) Control the solenoid valve 6 to open and close according to the optimal pulsation frequency, so as to transform the intake airflow into a pulsating airflow with the optimal pulsation frequency;

[0090] 24) Start motor 10 to drive screw feeder 11 to supply cutting dust into the cavity according to the set feed flow rate until the weighing sensor measures that the total weight of the cutting dust fed is equal to the set weight.

[0091] 25) Turn off motor 10, first axial flow fan 3 and second axial flow fan 12, weigh the cutting dust deposited in cavity 1, and obtain the j-th purification coefficient;

[0092] 26) Plot the j-th point corresponding to the j-th purification coefficient and the j-th intake air velocity in the purification coefficient-intake air velocity coordinate system, and fit the first point to the i-th point into a smooth curve of purification coefficient-intake air velocity.

[0093] 27) Determine whether the purification coefficient-intake air velocity smooth curve has a monotonically increasing range and a monotonically decreasing curve: if yes, then take the intake air velocity corresponding to the peak of the purification coefficient-intake air velocity smooth curve as the optimal intake air velocity of the cavity; if no, proceed to step 28).

[0094] 29) Increase the j-th wind speed according to the set rule, let j = j + 1, and repeat step 21).

[0095] This verifies that the purification coefficient first increases and then decreases with the increase of the intake air velocity, so the intake air velocity corresponding to the maximum purification coefficient can be obtained by curve fitting.

[0096] Specifically, the second method for measuring the cutting dust purification coefficient includes the following steps:

[0097] S1: Determine the optimal intake air velocity

[0098] S11) Control the rotation speed of the first axial flow fan 3 and the second axial flow fan 12 respectively, so that the intake air speed is the nth air speed;

[0099] S12) Adjust the opening of the electric ball valve 5 to the set opening, so that the air intake flow rate is the nth air intake flow rate at the nth wind speed;

[0100] S13) Control the solenoid valve 6 to open and close at a set frequency, so as to convert the intake airflow into a pulsating airflow with a set pulsating frequency.

[0101] S14) Start motor 10 to drive screw feeder 11 to supply cutting dust into the cavity according to the set feed flow rate until the weighing sensor measures that the total weight of the cutting dust fed is equal to the set weight.

[0102] S15) Turn off motor 10, first axial flow fan 3 and second axial flow fan 12, weigh the cutting dust deposited in cavity 1, and obtain the j-th purification coefficient;

[0103] S16) Plot the nth point corresponding to the nth purification coefficient and the nth intake air velocity in the purification coefficient-intake air velocity coordinate system, and fit the first point to the nth point into a purification coefficient-intake air velocity smooth curve.

[0104] S17) Determine whether the purification coefficient-intake air speed smooth curve has a monotonically increasing range and a monotonically decreasing curve: if yes, then take the intake air speed corresponding to the peak of the purification coefficient-intake air speed smooth curve as the optimal intake air speed of the cavity; if no, proceed to step S18).

[0105] S18) Increase the nth wind speed according to the set rule, let n = n + 1, and repeat step S11 in a loop.

[0106] This verifies that the purification coefficient first increases and then decreases with the increase of the intake air velocity, so the intake air velocity corresponding to the maximum purification coefficient can be obtained by curve fitting.

[0107] Step S2: Determine the optimal pulsation frequency

[0108] S21) Control the speed of the first axial flow fan and the second axial flow fan to the set speed respectively, so that the intake air speed is the optimal intake air speed;

[0109] S22) Adjust the opening of the electric ball valve to the set opening to make the intake flow rate the optimal airflow rate under the optimal intake wind speed;

[0110] S23) Control the solenoid valve to open and close at a set frequency m, so as to convert the intake airflow into a pulsating airflow with a set frequency m.

[0111] S24) Start the motor to drive the screw feeder to supply cutting dust into the cavity according to the set feed flow rate until the weighing sensor measures that the total weight of the cutting dust fed is equal to the set weight.

[0112] S25) Turn off the motor, the first axial flow fan and the second axial flow fan, weigh the cutting dust deposited in the cavity, and obtain the m-th purification coefficient;

[0113] S26) Plot the m-th point corresponding to the m-th purification coefficient and the m-th frequency in the purification coefficient-frequency coordinate system, and fit the points from the 1st point to the m-th point into a purification coefficient-frequency smooth curve;

[0114] S27) Determine whether the purification coefficient-frequency smoothing curve has a monotonically increasing interval and a monotonically decreasing curve: if yes, then take the frequency corresponding to the peak of the purification coefficient-frequency smoothing curve as the optimal pulsation frequency of the cavity and execute step two; if no, execute step S28).

[0115] S28) Increase the frequency of the pulsating airflow according to the set rule, let m = m + 1, and repeat step S21 in a loop.

[0116] This verifies the variation law that the purification coefficient first increases and then decreases with the increase of the pulsation frequency of the intake airflow. Therefore, the pulsation frequency corresponding to the maximum purification coefficient can be obtained by curve fitting.

[0117] The above-described embodiments are merely preferred embodiments provided to fully illustrate the present invention, and the scope of protection of the present invention is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on the present invention are all within the scope of protection of the present invention. The scope of protection of the present invention is defined by the claims.

Claims

1. A cutting dust purification coefficient measuring device, characterized by: The mould cavity is provided with a cavity air inlet and a cavity air outlet; the cavity air inlet is connected with a positive pressure air inlet system and a cutting dust feeding system; the cavity air outlet is connected with a negative pressure air outlet system; The positive pressure air inlet system comprises a first axial flow fan, the air inlet of the first axial flow fan is connected with a first filter, the air outlet of the first axial flow fan is connected with the cavity air inlet through a valve group, the valve group comprises a series connection of an electric ball valve and an electromagnetic valve, and the electric ball valve is located between the electromagnetic valve and the first axial flow fan; the electric ball valve controls the air inlet flow by adjusting the opening degree, and the electromagnetic valve adjusts the air inlet frequency by opening and closing control; The cutting dust feeding system comprises a cutting dust storage bin for storing cutting dust and a screw feeder driven by a motor and used for conveying cutting dust, the cutting dust storage bin is provided below with a weighing sensor; a three-way pipe is arranged between the valve group and the cavity air inlet, and the discharge port of the screw feeder is connected with the three-way pipe; The negative pressure air outlet system comprises a second axial flow fan, the air inlet of the second axial flow fan is connected with the cavity air outlet, and the air outlet of the second axial flow fan is connected with a second filter; The control system is electrically connected with the first axial flow fan, the second axial flow fan, the electric ball valve, the electromagnetic valve, the motor and the weighing sensor respectively, and: The control system controls the air inlet wind speed by controlling the rotating speed of the first axial flow fan and the second axial flow fan respectively; The control system adjusts the air inlet flow by controlling the opening degree of the electric ball valve; The control system changes the air inlet flow into a pulsating flow and adjusts the frequency of the pulsating flow by controlling the opening and closing of the electromagnetic valve; The control system controls the rotating speed and start-stop of the motor according to the weight data collected by the weighing sensor in real time, so as to control the feeding flow and total weight of the cutting dust.

2. The cutting dust clean-up factor measuring device according to claim 1, characterized in that: The first axial flow fan is connected in series with at least two first axial flow fans.

3. The cutting dust clean-up factor measuring device of claim 1, wherein: A first particle concentration sensor for detecting the concentration of cutting dust is arranged between the first filter and the first axial flow fan; a second particle concentration sensor is arranged at the air outlet of the second filter; a third particle concentration sensor for detecting the concentration of cutting dust is arranged in the cavity.

4. The cutting dust clean-up factor measuring device of claim 1, wherein: A thermal gas mass flow meter is arranged between the three-way pipe and the valve group, and the thermal gas mass flow meter is connected with the control system to monitor the air inlet flow and air inlet wind speed in real time.

5. The cutting dust clean-up factor measuring device of claim 1, wherein: The cavity is made of transparent material.

6. The cutting dust clean-up factor measuring device of claim 5, wherein: An observation system is further included, the observation system comprises a data acquisition system and high-speed cameras, the high-speed cameras are arranged in two, and the two high-speed cameras observe the movement track and collision-deposition behavior of the cutting dust flow in the cavity from two mutually perpendicular directions respectively.

7. The cutting dust clean-up factor measuring device of claim 1, wherein: Tinfoil is attached to the bottom of the cavity for collecting the deposited cutting dust.

8. The cutting dust clean-up factor measuring device of claim 1, wherein: A gas differential pressure meter for detecting the pressure difference between the cavity air inlet and the cavity air outlet is arranged in the cavity.

9. A method of measuring a cutting dust purification coefficient, characterized by: The cutting dust purification coefficient measuring device is realized based on any one of claims 1-8, comprising the following steps: Step one: determining the optimal pulsating frequency 11) control the rotating speed of the first and second axial flow fans to be the set rotating speed, so that the air inlet speed is the set speed; 12) adjust the opening of the electric ball valve to be the set opening, so that the air inlet flow is the set flow; 13) control the electromagnetic valve to open and close at the set i-th frequency, so that the air inlet flow is changed into a pulsating flow with the set i-th frequency; 14) start the motor to drive the screw feeder to supply the cutting dust into the cavity at the set feeding flow, until the total weight of the cutting dust measured by the weighing sensor is equal to the set weight; 15) turn off the motor, the first and second axial flow fans, and weigh the cutting dust deposited in the cavity to obtain the i-th purification coefficient; 16) plot the i-th point corresponding to the i-th purification coefficient and the i-th frequency on the purification coefficient-frequency coordinate system, and fit the first point to the i-th point to be a smooth purification coefficient-frequency curve; 17) determine whether the smooth purification coefficient-frequency curve has a monotonically increasing interval and a monotonically decreasing interval: if yes, take the frequency corresponding to the vertex of the smooth purification coefficient-frequency curve as the optimal pulsating frequency of the cavity, and execute step two; if no, execute step 18); 18) increase the frequency of the pulsating flow according to a set rule, let i=i+1, and execute steps 11) to 17) cyclically; Step two: determine the optimal air inlet speed 21) control the rotating speed of the first and second axial flow fans respectively, so that the air inlet speed is the j-th speed; 22) adjust the opening of the electric ball valve to be the set opening, so that the air inlet flow is the j-th air inlet flow at the j-th speed; 23) control the electromagnetic valve to open and close at the optimal pulsating frequency, so that the air inlet flow is changed into a pulsating flow with the optimal pulsating frequency; 24) start the motor to drive the screw feeder to supply the cutting dust into the cavity at the set feeding flow, until the total weight of the cutting dust measured by the weighing sensor is equal to the set weight; 25) turn off the motor, the first and second axial flow fans, and weigh the cutting dust deposited in the cavity to obtain the j-th purification coefficient; 26) plot the j-th point corresponding to the j-th purification coefficient and the j-th air inlet speed on the purification coefficient-air inlet speed coordinate system, and fit the first point to the j-th point to be a smooth purification coefficient-air inlet speed curve; 27) determine whether the smooth purification coefficient-air inlet speed curve has a monotonically increasing interval and a monotonically decreasing interval: if yes, take the air inlet speed corresponding to the vertex of the smooth purification coefficient-air inlet speed curve as the optimal air inlet speed of the cavity; if no, execute step 28); 28) increase the j-th speed according to a set rule, let j=j+1, and execute steps 21) to 27) cyclically.

10. A method of measuring a cutting dust purification coefficient, characterized by: The cutting dust purification coefficient measuring device is realized based on any one of claims 1-8, and comprises the following steps: S1: determine the optimal air inlet speed S11) control the rotating speed of the first and second axial flow fans respectively, so that the air inlet speed is the n-th speed; S12) adjust the opening of the electric ball valve to be the set opening, so that the air inlet flow is the n-th air inlet flow at the n-th speed; S13) controlling the electromagnetic valve to open and close at a set frequency to convert the intake airflow into a pulsating airflow with a set pulsation frequency; S14) starting the motor to drive the screw feeder to supply the cutting dust into the cavity at a set feeding flow rate until the weighing sensor measures that the total weight of the cutting dust is equal to the set weight; S15) turning off the motor, the first axial fan and the second axial fan, and weighing the cutting dust deposited in the cavity to obtain the nth purification coefficient; S16) plotting the nth point corresponding to the nth purification coefficient and the nth intake air speed on the purification coefficient-intake air speed coordinate system, and fitting the first point to the nth point as a smooth purification coefficient-intake air speed curve; S17) determining whether the smooth purification coefficient-intake air speed curve has a monotonically increasing interval and a monotonically decreasing interval: if yes, taking the intake air speed corresponding to the vertex of the smooth purification coefficient-intake air speed curve as the optimal intake air speed of the cavity; if no, executing step S18); S18) increasing the nth air speed according to a set rule, letting n = n + 1, and executing steps S11) to S17) cyclically; Step S2: determining the optimal pulsation frequency S21) respectively controlling the rotational speeds of the first axial fan and the second axial fan to be set rotational speeds so that the intake air speed is the optimal intake air speed; S22) adjusting the opening of the electric ball valve to be a set opening so that the intake flow rate is the optimal flow rate under the optimal intake air speed; S23) controlling the electromagnetic valve to open and close at a set mth frequency to convert the intake airflow into a pulsating airflow with a set mth frequency; S24) starting the motor to drive the screw feeder to supply the cutting dust into the cavity at a set feeding flow rate until the weighing sensor measures that the total weight of the cutting dust is equal to the set weight; S25) turning off the motor, the first axial fan and the second axial fan, and weighing the cutting dust deposited in the cavity to obtain the mth purification coefficient; S26) plotting the mth point corresponding to the mth purification coefficient and the mth frequency on the purification coefficient-frequency coordinate system, and fitting the first point to the mth point as a smooth purification coefficient-frequency curve; S27) determining whether the smooth purification coefficient-frequency curve has a monotonically increasing interval and a monotonically decreasing interval: if yes, taking the frequency corresponding to the vertex of the smooth purification coefficient-frequency curve as the optimal pulsation frequency of the cavity; if no, executing step S28); S28) increasing the frequency of the pulsating airflow according to a set rule, letting m = m + 1, and executing steps S21) to S27) cyclically.

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