A portable flotation aeration rate testing instrument and measurement method

Abstract

This invention provides a portable flotation aeration rate testing instrument and measurement method. The instrument includes a mechanical package and instruments installed within the mechanical package. The mechanical package includes a front cover, a middle cover, an inner cover, a rear cover, a battery cover, a variable diameter guide pipe, and an exhaust pipe. The front and rear covers are closed, with the middle cover located between them. The inner cover is fixed to the middle cover, and the battery cover is located inside the middle cover. The instruments include a miniature thermal flow meter, an LCD screen, a switch, a microcontroller, and a lithium battery power supply. The miniature thermal flow meter is fixed inside the middle cover with bolts, the LCD screen is fixed to the inner cover with adhesive, the switch is fixed to the inner cover, the microcontroller is fixed to the middle cover, and the lithium battery power supply is located inside the middle cover. This invention reduces testing steps and equipment weight during measurement, eliminates experimental errors caused by visual observation of liquid level changes and manual timing, avoids installing too many instruments, and saves costs.

Description

Technical Field

[0001] This invention relates to the field of flotation machine technology, and in particular to a portable flotation aeration rate testing instrument and measurement method. Background Technology

[0002] In recent years, the beneficiation of useful minerals has become increasingly difficult. During flotation, the phenomenon of "mudification" often occurs due to the excessively fine particles, or the crystals of the target mineral and impurity particles are difficult to separate, resulting in increased beneficiation difficulty, low resource utilization, low separation efficiency, and poor process adaptability of large flotation equipment.

[0003] The apparent aeration rate has a significant impact on the mineralization process of bubbles, flotation rate, and process parameters. Traditional methods for measuring the aeration rate of flotation machines involve installing sensors on each flotation unit and feeding data back to a CNC center via a PLC to monitor the real-time aeration rate (using a fixed aeration rate tester) or measuring the aeration rate using the water displacement and gas collection method. The former method cannot be used for digital process analysis and has excessively high installation costs, while the latter has drawbacks such as cumbersome operation, insufficient protection of personnel safety during testing, and low measurement accuracy. Summary of the Invention

[0004] The purpose of this invention is to develop a portable flotation aeration rate testing instrument and method. The instrument's external test tube is inserted into the slurry. Rising foam bursts, generating airflow. This airflow rises along the tube wall and is collected into a miniature thermal flow meter using a designed flow guiding device. The microcontroller then feeds back the airflow signal data to the display screen, showing the real-time airflow value and the average airflow value measured over a set time period, thus completing the flotation aeration rate test. The microcontroller design of this instrument solves the problem of the inability to conduct digital process analysis. By using the airflow detection method, the previous method of water displacement and air collection is eliminated, reducing testing steps and equipment weight, and improving testing safety. Data recording by sensors and the microcontroller eliminates the testing errors caused by visual observation of liquid level changes and manual timing. The portable design avoids the installation of excessive instruments, saving on instrument installation costs.

[0005] On one hand, the present invention provides a portable flotation aeration rate testing instrument, comprising a mechanical package and instruments, wherein the instruments are installed within the mechanical package, which includes a front cover, a middle cover, an inner cover, a rear cover, a battery cover, a variable diameter guide pipe, and an exhaust pipe; the front cover and the rear cover are closed together, and the middle cover is located between the two; the inner cover is fixed to the middle cover, and the battery cover is located inside the middle cover; the instruments include a miniature thermal flow meter, an LCD screen, a switch, a microcontroller, and a lithium battery power supply, wherein the miniature thermal flow meter is fixed inside the middle cover by bolts, the LCD screen is fixed to the inner cover by adhesive, the switch is fixed to the inner cover, the microcontroller is fixed to the middle cover, and the lithium battery power supply is located inside the middle cover.

[0006] Preferably, the middle cover includes a middle cover buckle, a platform, an inner base of the middle cover, and a battery box. The middle cover buckle is used to connect the inner cover. The platform has a control wire passage and a test button passage. The side of the middle cover has a guide pipe installation passage and an exhaust pipe installation passage. The inner base of the middle cover and the battery box are located on the top of the platform.

[0007] Preferably, the inner cover adopts a stepped two-stage mounting panel. The first-stage mounting panel has a main power switch mounting port and a micro thermal flow meter observation port, and is equipped with an inner cover buckle that engages with the middle cover buckle. The second-stage mounting panel has a test switch mounting port and an LCD display observation port. The first-stage mounting panel is positioned higher than the second-stage mounting panel.

[0008] Preferably, the ratio of the diameter of the external glass air duct to the diameter of the air inlet pipe of the miniature thermal flow meter is 5:1.

[0009] Preferably, the inner diameters at both ends of the variable diameter guide tube are different.

[0010] Preferably, the exhaust pipe is a hollow cylindrical pipe.

[0011] Preferably, the smaller diameter end of the variable diameter guide pipe and the exhaust pipe are machined with the same internal threads as the two ends of the miniature thermal flow meter, and are respectively assembled at the two ends of the miniature thermal flow meter. The variable diameter guide pipe and the exhaust pipe pass through the guide pipe mounting passage and the exhaust pipe mounting passage on the side of the middle cover, respectively.

[0012] On the other hand, the present invention also provides a method for measuring inflation rate, which utilizes the above-mentioned portable flotation inflation rate measuring instrument and includes the following steps:

[0013] S1. Determine the locations of several test points for the required flotation aeration rates;

[0014] S2. After placing the portable flotation aeration rate measuring instrument above the test point, lower the device so that the glass air guide tube at the bottom is inserted 100-200mm into the surface of the slurry. Then press the main power switch in the switch to start the power. At this time, air will rise in the glass air guide tube to the flow test device. The flow test device will record the instantaneous value of the air volume. After the value measured by the flow test device stabilizes, press the test button to perform the aeration rate test.

[0015] S3. The microcontroller integrates and sums the instantaneous flow rate values, takes the mean and standard deviation, then removes outliers after small air volume deviation correction, integrates and sums the remaining values, divides by the number of remaining values ​​to calculate the average inflation rate, and finally divides by the cross-sectional area of ​​the glass air duct to obtain the inflation rate at the measurement location.

[0016] S4. Directly read the degree value as the inflation rate value at that point, record it, and then directly measure the next test point.

[0017] Preferably, the flow testing device uses a miniature gas flow meter.

[0018] Preferably, the microcontroller is powered by a lithium battery.

[0019] Compared with the prior art, the beneficial effects of the present invention are:

[0020] 1. A groundbreaking and innovative design was made to create a testing instrument that can test the aeration rate of a self-aspirating flotation machine, solving the problem that existing instruments cannot measure the aeration rate of a self-aspirating flotation machine.

[0021] 2. It is mobile and portable, overcoming the drawback of fixed inflation rate testers that require one to be installed at each test point, thus reducing installation costs;

[0022] 3. By recording data using a microcontroller, the experimental errors caused by observing liquid level changes by human eyes and timing by personnel are eliminated, further improving measurement accuracy;

[0023] 4. The flotation aeration rate is displayed by the air volume generated by the bursting of flotation foam. Compared with the traditional water drainage aeration method, the test process is greatly simplified, and the safety of personnel during the test process is also increased. Attached Figure Description

[0024] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the detection of a portable flotation aeration rate testing instrument according to an embodiment of the present invention;

[0026] Figure 2 This is a schematic diagram of the mechanical packaging shell according to an embodiment of the present invention;

[0027] Figure 3 This is a schematic diagram of the structure of the instrumentation according to an embodiment of the present invention;

[0028] Figure 4 This is a schematic diagram of the cover structure in an embodiment of the present invention;

[0029] Figure 5 This is a schematic diagram of the variable diameter guide tube structure according to an embodiment of the present invention;

[0030] Figure 6 This is a schematic diagram of the exhaust pipe structure according to an embodiment of the present invention;

[0031] Figure 7 This is a schematic diagram of the inner cover structure according to an embodiment of the present invention;

[0032] Figure 8 This is a schematic diagram of the front cover structure according to an embodiment of the present invention;

[0033] Figure 9 This is a schematic diagram of the rear cover structure according to an embodiment of the present invention;

[0034] Figure 10 This is a structural diagram of the instrumentation system according to an embodiment of the present invention;

[0035] Figure 11 This is a software flowchart of an embodiment of the present invention.

[0036] Explanation of reference numerals in the attached figures:

[0037] 1: Mechanical packaging; 2: Instrumentation; 11: Front cover; 12: Middle cover; 1201: Middle cover clip; 1202: Platform; 120201: Internal base of the middle cover; 120202: Battery box; 120203: Control wire access port; 120204: Test button access port; 120205: First mounting hole; 120206: Second mounting hole; 1203: Guide tube mounting port; 1204: Exhaust pipe mounting port; 13: Inner cover; 13 01: Main power switch mounting port; 1302: Test switch mounting port; 1303: Miniature thermal flow meter observation port; 1304: LCD display observation port; 1305: Inner cover buckle; 14: Rear cover; 15: Battery cover; 16: Variable diameter guide pipe; 1601: Small diameter of variable diameter guide pipe; 1602: Large diameter of variable diameter guide pipe; 17: Exhaust pipe; 21: Miniature thermal flow meter; 22: LCD display; 23: Switch; 24: Microcontroller; 25: Lithium battery power supply. Detailed Implementation

[0038] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. 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.

[0039] 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 used 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 limiting this invention.

[0040] 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 indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. Furthermore, the terms "installed," "connected," and "linked" should be interpreted broadly; for example, they may refer to a fixed connection, a detachable connection, or an integral connection; they may refer to a mechanical connection or an electrical connection; they may refer to a direct connection or an indirect connection through an intermediate medium; and they may refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0041] like Figures 1 to 3As shown, this invention provides a portable flotation aeration rate testing instrument, including a mechanical package and instruments. The instruments are installed within the mechanical package, which includes a front cover 11, a middle cover 12, an inner cover 13, a rear cover 14, a battery cover 15, a variable diameter guide pipe 16, and an exhaust pipe 17. The front cover 11 and the rear cover 14 are closed, with the middle cover 12 located between them. The inner cover 13 is fixed to the middle cover 12, and the battery cover 15 is located inside the middle cover 12. The instruments include a miniature thermal flow meter 21, an LCD screen 22, a switch 23, a microcontroller 24, and a lithium battery power supply 25. The miniature thermal flow meter 21 is fixed inside the middle cover 12 by bolts, the LCD screen 22 is fixed to the inner cover 13 by adhesive, the switch 23 is fixed to the inner cover 13, the microcontroller 24 is fixed to the middle cover 12, and the lithium battery power supply 25 is located inside the middle cover 12.

[0042] The front cover 11 is made by carving a boss into a cylinder, with internal threads machined on the inner side of the lower end, and a high-transparency thin sheet attached to the top for numerical observation. The rear cover 14 is made by machining an annular cylinder on the upper surface of a column, with external threads machined on the outer side of the annular cylinder area. The upper end of the middle cover 12 has external threads to mate with the front cover 11, which has internal threads, and the lower end has internal threads to mate with the rear cover 14, which has external threads.

[0043] like Figures 4 to 6 As shown, the middle cover 12 includes a middle cover buckle 1201, a platform 1202, an inner base 120201, and a battery box 120202. The middle cover buckle 1201 is used to connect the inner cover 13. The platform 1202 has a control wire passage 120203 and a test button passage 120204. The side of the middle cover 12 has a guide pipe installation passage 1203 and an exhaust pipe installation passage 1204. The battery box 120202 is located on the top of the platform 1202. The base and the platform are designed with multiple round holes, such as the first mounting hole 120205 and the second mounting hole 120206, for sealing and fixing electronic devices. A cuboid is designed at the center of the platform 12. A cuboid of an appropriate size is cut out from the center of the back of the platform 1202 to form the inner base 120201 of the middle cover. Two first mounting holes 120205 are machined on the upper surface of the inner base 120201 of the middle cover. The miniature thermal flow meter 21 is fixed to the upper surface of the inner base 120201 of the middle cover with bolts. The miniature thermal flow meter 21 has external threads at both ends.

[0044] The variable diameter guide tube 16 consists of a hollow frustum and its extended hollow cylinder, while the exhaust pipe 17 is a hollow cylindrical tube. The smaller diameter of the variable diameter guide tube 16 and one end of the exhaust pipe 17 are machined with the same internal threads as both ends of the miniature thermal flow meter 21, and are respectively assembled at both ends of the miniature thermal flow meter 21. Simultaneously, the variable diameter guide tube 16 and the exhaust pipe 7 pass through the guide tube mounting port 1203 and the exhaust pipe mounting port 1204 on the side of the middle cover 12, respectively. The ratio of the diameter of the external glass air guide tube to the diameter of the air inlet pipe of the miniature thermal flow meter 21 is 5:1.

[0045] The side of the variable diameter guide tube 16 is structurally designed. To simplify the calculation, the air is now considered as an incompressible gas. The flow rate and velocity of the gas flowing in and out can be calculated. The designed side structure should ensure that the flow rate of the gas in and out satisfies the continuity equation, as shown in equation (1).

[0046] S i V i =S o V o (1)

[0047] In the formula, S i V is the cross-sectional area of ​​the entrance. i S represents the inlet gas velocity. o V is the cross-sectional area of ​​the outlet. o The outlet gas velocity.

[0048] Calculations based on Bernoulli's equation show that this design significantly reduces gas pressure drop losses. The principle of this miniature thermal flow meter 21 is that the airflow is measured by the flow meter and converted into an analog signal, which is then transmitted to the microcontroller 24 for processing. The data is then fed back to the LCD screen 22. The unit displayed here is L / min, which is the volume of air flowing through the thermal flow meter per unit time.

[0049] The inner cover 13 adopts a stepped two-stage mounting panel. The first-stage mounting panel has a main power switch mounting port 1301 and a micro thermal flow meter observation port 1303, and is equipped with an inner cover buckle 1305, which is fastened to the middle cover buckle 1201. The second-stage mounting panel has a test switch mounting port 1302 and an LCD display observation port 1304. The first-stage mounting panel is set higher than the second-stage mounting panel. The main power switch and the test button are fixed in the positions of the main power switch mounting port 1301 and the test switch mounting port 1302, respectively. The LCD display 22 is fixed to the lower edge of the LCD display observation port 1304 with adhesive. The inner cover buckle 1305 is fastened to the middle cover buckle 1201, so that the inner cover 13 is fixed on the middle cover 12. At this time, the display of the micro thermal flow meter 21 passes through the micro thermal flow meter observation port 1304 located in the middle of the inner cover 12.

[0050] The present invention also provides a method for measuring inflation rate, which utilizes the aforementioned portable flotation inflation rate measuring instrument and includes the following steps:

[0051] S1. Determine the locations of several test points for the required flotation aeration rates, for example, determine 6 points;

[0052] S2. After placing the portable flotation aeration rate measuring instrument above the test point, lower the device so that the glass air guide tube at the bottom is inserted 100-200mm into the surface of the slurry. Then, press the main power switch in switch 23 to start the power. At this time, air will rise in the glass air guide tube to the flow test device. The flow test device will record the instantaneous value of the air volume. After the value measured by the flow test device stabilizes, press the test button. The device will start running for 120 seconds to perform the aeration rate test.

[0053] S3, the microcontroller 24 integrates and sums the collected instantaneous flow values ​​and then takes the average value. The average inflation rate is calculated by taking the standard deviation σ, correcting for small air volume deviations, removing outliers, integrating and summing the remaining values, dividing by the number of remaining values, and finally dividing by the cross-sectional area of ​​the glass air tube to obtain the inflation rate at the measurement location.

[0054] The working principle of this invention is as follows: The slurry in the flotation equipment contains a large number of air bubbles. These air bubbles have a relatively small specific gravity compared to the slurry, so they rise due to buoyancy. During the rising process, the external pressure of the slurry continuously decreases, while the internal pressure of the air bubbles remains unchanged. As the air bubbles rise, they gradually increase in size, and the hydration film on the surface of the air bubbles becomes thinner. When they reach the liquid surface, the pressure difference between the inside and outside of the air bubbles reaches its maximum value, and the hydration film ruptures first, followed by the rupture of the entire air bubble. When a large number of air bubbles rupture, a measurable micro-airflow is formed.

[0055] The data processing logic is as follows:

[0056] Calculate the mean and standard deviation of the 1200 recorded data points according to formula (2).

[0057]

[0058] when If the condition is met, record the point; otherwise, discard it.

[0059] Where n is the correction parameter, m is the number of measurement records, and X m This represents the inflation rate value recorded for the m-th time.

[0060] Then the inflation rate Q at that point is:

[0061]

[0062] In the formula, t is the number of points to be removed, and S is the cross-sectional area.

[0063] S4. Directly read the degree value as the inflation rate value at that point, record it, and then directly measure the next test point.

[0064] To further determine the value of the correction factor n, measurements were taken using a fixed inflation rate tester and the instrument under the same conditions. The difference Q calculated by the two methods was calculated using equation (4). e .

[0065] Q e =|Q In -Q fix | (4)

[0066] In the formula Q In Q is the value of the inflation rate measured using this instrument. fix The value of the inflation rate measured by a fixed inflation rate tester.

[0067] Through experiments, the correction coefficient n value and Q e The relationship is shown in Table 1.

[0068]

[0069] Based on the above value, the selected correction factor n can be tentatively set to 2.5.

[0070] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A portable movable flotation air rate test instrument, characterized in that, The device includes a mechanical package and instruments. The instruments are installed within the mechanical package, which includes a front cover (11), a middle cover (12), an inner cover (13), a rear cover (14), a battery cover (15), a variable diameter guide pipe (16), and an exhaust pipe (17). The front cover (11) is closed to the rear cover (14), and the middle cover (12) is located between the two. The inner cover (13) is fixed to the middle cover (12), and the battery cover (15) is located inside the middle cover (12). The instruments include a miniature thermal flow meter (21) and an LCD. The system includes a display screen (22), a switch (23), a microcontroller (24), and a lithium battery power supply (25). The miniature thermal flow meter (21) is fixed inside the middle cover (12) by bolts. The LCD display screen (22) is fixed to the inner cover (13) by adhesive. The switch (23) is fixed to the inner cover (13). The microcontroller (24) is fixed to the middle cover (12). The lithium battery power supply (25) is located inside the middle cover (12). The middle cover (12) includes a middle cover buckle (1201), a table (1202), and an inner base (1203). 201) and battery box (120202), the middle cover buckle (1201) is used to connect the inner cover (13); the table surface (1202) is provided with a control wire passage (120203) and a test button passage (120204), the side of the middle cover (12) is provided with a guide pipe installation passage (1203) and an exhaust pipe installation passage (1204); the inner base (120201) of the middle cover and the battery box (120202) are set on the top of the table surface (1202); the diameter of the external glass guide pipe is the same as that of the micro thermal flow meter ( The intake pipe diameter ratio of 21) is 5:1; the inner diameters of the two ends of the variable diameter guide pipe (16) are different; the exhaust pipe (17) is a hollow cylindrical pipe; the smaller diameter end of the variable diameter guide pipe (16) and the exhaust pipe (17) are machined with the same internal threads as the two ends of the micro thermal flow meter (21), and are respectively assembled at the two ends of the micro thermal flow meter (21). The variable diameter guide pipe (16) and the exhaust pipe (17) pass through the guide pipe installation passage (1203) and the exhaust pipe installation passage (1204) on the side of the middle cover (12), respectively.

2. The portable movable flotation gas rate test instrument according to claim 1, wherein, The inner cover (13) adopts a stepped two-stage mounting panel. The first-stage mounting panel has a main power switch mounting port (1301) and a micro thermal flow meter observation port (1303), and is equipped with an inner cover buckle (1305), which is fastened to the middle cover buckle (1201). The second-stage mounting panel has a test switch mounting port (1302) and an LCD screen observation port (1304). The first-stage mounting panel is set higher than the second-stage mounting panel.

3. A method of measuring the rate of air entrainment using the portable, movable, floating, rate-of-air-entrainment measuring instrument of any one of claims 1 to 2, characterized in that, Includes the following steps: S1. Determine the locations of several test points for the required flotation aeration rates; S2. After placing the portable flotation aeration rate measuring instrument above the test point, lower the device so that the glass air guide tube at the bottom is inserted 100-200mm into the surface of the slurry. Then press the main power switch in switch (23) to start the power. At this time, air will rise in the glass air guide tube to the flow test device. The flow test device will record the instantaneous value of the air volume. After the value measured by the flow test device stabilizes, press the test button to perform the aeration rate test. The principle of airflow formation is as follows: The slurry in the flotation equipment contains a large number of air bubbles. These air bubbles have a relatively small specific gravity compared to the slurry, so they rise due to buoyancy. During the rise, the external pressure of the slurry continuously decreases, while the internal pressure of the air bubbles remains constant. As the air bubbles rise, they gradually increase in size, and the hydration film on the surface of the air bubbles becomes thinner. When they reach the liquid surface, the pressure difference between the inside and outside of the air bubble reaches its maximum value, and the hydration film ruptures first, followed by the rupture of the entire air bubble. When a large number of air bubbles rupture, a measurable micro-airflow is formed. S3. The microcontroller (24) integrates and sums the instantaneous flow rate values ​​and takes the mean and standard deviation. Then, after correcting for small air volume deviations, it removes the outliers and integrates and sums the remaining values. Then, it divides the sum by the number of remaining values ​​to calculate the average inflation rate. Finally, it divides the sum by the cross-sectional area of ​​the glass air duct to obtain the inflation rate at the measurement position. S4. Directly read the degree value as the inflation rate value at that point, record it, and then directly measure the next test point.

4. The inflation rate measurement method according to claim 3, characterized in that, The flow testing device uses a miniature gas flow meter.

5. The inflation rate measurement method according to claim 3, characterized in that, The microcontroller (24) is powered by a lithium battery power supply (25).

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