Coal slime flotation reagent precise dosing device and redundant flowmeter detection checking method

Abstract

The present application relates to a kind of coal slime flotation reagent precision dosing device and redundancy flowmeter detection check method, belong to coal separation processing technical field, solve the problem of reagent addition inaccuracy in coal slime flotation process in prior art.The present application includes first main pipeline, first branch, second branch, first buffer pipeline, second buffer pipeline and second main pipeline, first branch and second branch are in parallel, first buffer pipeline and second buffer pipeline are in parallel, the front end of first branch, the front end of second branch and the end of first main pipeline are communicated simultaneously, the end of first branch and the front end of first buffer pipeline are communicated, the end of second branch and the front end of second buffer pipeline are communicated, the rear end of first buffer pipeline and the rear end of second buffer pipeline and the front end of second main pipeline are communicated simultaneously.The present application can realize single reagent double pump precision control, multiple flowmeter detection check, to realize the precision dosing control of flotation reagent, can accurately control coal slime flotation reagent addition amount.

Description

Technical Field

[0001] This invention relates to the field of coal sorting and processing technology, and in particular to a precise dosing device for coal slime flotation reagents and a method for detecting and verifying redundant flow meters. Background Technology

[0002] Coal is a major energy source in my country, and flotation is an important method for coal preparation, effectively treating coal slime with a particle size of less than 0.5 mm. By adding flotation reagents to the slurry and utilizing the difference in hydrophobicity between the surfaces of coal and gangue, along with the introduction of air bubbles and thorough agitation, coal and gangue can be effectively separated. In most coal preparation plants, flotation accounts for 20% to 30% of the raw coal processing volume; therefore, the effectiveness of flotation operations has a significant impact on the economic benefits of the coal preparation plant. The type and dosage of collectors and frothers added during flotation are crucial.

[0003] Coal preparation plant flotation operations require the addition of various chemical reagents such as diesel and fusel oil. The traditional method of adding reagents is to add them directly into the flotation machine or into the mixing tank. After determining the amount of reagent to be added, the on-site workers manually adjust the opening of the reagent self-flow valve. The adjustment is affected by the liquid level in the reagent tank and the flotation flow field. Adjusting the reagent dosage through the self-flow valve results in large fluctuations in the reagent dosage, which may cause changes in flotation indicators and cannot meet the requirements for precise control and ash control for specific coal types.

[0004] Automatic dosing machines can achieve stable drug delivery through autonomous inhalation and pressurization. After setting the parameters, they can automatically extract collectors and frothers, add them to the mixing tank, precisely control the dosage within a fixed time, and monitor the flow rate in real time to ensure that the actual flow rate remains stable within a certain range. Existing automatic dosing machines often use a single metering pump and single instrument design, which cannot guarantee dosing accuracy at high volumes and often lacks fault diagnosis methods such as flow rate calibration. Summary of the Invention

[0005] Based on the above analysis, the present invention aims to provide a precise dosing device for coal slime flotation reagents based on dual metering pumps and a redundant flow meter detection and verification method to solve the problem of inaccurate reagent addition in the existing coal slime flotation process.

[0006] On one hand, the present invention provides a precise dosing device for coal slime flotation reagents based on dual metering pumps, including a first main pipeline, a first branch pipeline, a second branch pipeline, a first buffer pipeline, a second buffer pipeline, and a second main pipeline. The first branch pipeline and the second branch pipeline are connected in parallel, and the first buffer pipeline and the second buffer pipeline are connected in parallel. The front ends of the first branch pipeline and the second branch pipeline are simultaneously connected to the end of the first main pipeline. The end of the first branch pipeline is connected to the front end of the first buffer pipeline, and the end of the second branch pipeline is connected to the front end of the second buffer pipeline. The rear ends of the first buffer pipeline and the rear ends of the second buffer pipeline are simultaneously connected to the front end of the second main pipeline.

[0007] Furthermore, the first main pipeline is equipped with a bag filter, a shut-off valve, and a Y-type filter.

[0008] Furthermore, the first branch is provided with a first check valve and a first dosing pump, with the first dosing pump located downstream of the first check valve.

[0009] Furthermore, the first branch is also equipped with a first pressure gauge.

[0010] Furthermore, the first branch is also equipped with a first switching valve.

[0011] Furthermore, a second check valve and a second dosing pump are provided on the second branch, with the second dosing pump located downstream of the second check valve.

[0012] Furthermore, the second branch is also equipped with a second pressure gauge and a second switching valve.

[0013] Furthermore, the second main pipeline is equipped with a buffer observation tank and a fifth flow meter.

[0014] On the other hand, the present invention provides a dosing control method based on dual metering pumps. Using the above-mentioned coal slime flotation reagent precision dosing device, for the target dosing amount SP, the first dosing pump is first controlled to reach 90% of the target dosing amount SP, and then the residual of the target dosing amount SP is compensated by the second dosing pump.

[0015] On the other hand, the present invention provides a redundant flow meter detection and verification method, which uses the flow meter in the above-mentioned coal slime flotation reagent precision dosing device for verification.

[0016] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0017] (1) This invention can realize precise control of single reagent dual pump and multi-flow meter detection and verification, thereby realizing precise dosing control of flotation reagent. The reagent is sucked in by mechanical diaphragm pump and negative pressure, and with the help of filter, a negative pressure inlet is formed. The reagent is pressurized by two branch pumps for coarse and fine adjustment. The pressurized reagent flows out from the outlet after passing through the buffer pipeline and the branch reagents are combined. The actual flow rate is verified by the branch flow meter and the total reagent flow meter, and then feedback control is performed to accurately control the dosing amount.

[0018] (2) The first main pipeline of the present invention is equipped with a bag filter and a Y-type filter. The bag filter and the Y-type filter are used to perform double filtration of the pretreatment of the drug at the feed end, reducing impurities in the drug and facilitating precise control of the dosage.

[0019] (3) In this invention, the high-range metering pump is first controlled to reach 90% of the target dosage, and then the residual of the target dosage is compensated by the low-range high-precision metering pump. The agent is coarsely and finely adjusted by the pressurization of the two branch pumps, which improves the control accuracy of the dosage.

[0020] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages may become apparent from the description or be learned by practicing the invention. The objects and other advantages of this invention can be realized and obtained from what is particularly pointed out in the description and drawings. Attached Figure Description

[0021] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0022] Figure 1 This is a schematic diagram of a precision dosing device for flotation reagents in a specific embodiment;

[0023] Figure 2 This is a schematic diagram of the buffer observation tank in a specific embodiment;

[0024] Figure 3 This is a cross-sectional schematic diagram of the buffer observation liquid tank in a specific embodiment;

[0025] Figure 4 This is a schematic diagram of the dual-pump feedforward control dosing logic of the present invention.

[0026] Figure label:

[0027] 100-First main pipeline; 101-Bag filter; 102-Stop valve; 103-Y-type filter; 200-First branch; 201-First check valve; 202-First dosing pump; 203-First safety valve; 204-First pressure gauge; 205-First switching valve; 300-Second branch; 301-Second check valve; 302-Second dosing pump; 303-Second safety valve; 304-Second pressure gauge; 305-Second switching valve; 400-First buffer pipeline; 401-First buffer chamber; 402-... 1. Damping pulsation damper; 403-First flow meter; 404-First back pressure valve; 405-Second flow meter; 500-Second buffer pipeline; 501-Second buffer chamber; 502-Second damping pulsation damper; 503-Third flow meter; 504-Second back pressure valve; 505-Fourth flow meter; 600-Second main pipeline; 601-Buffer observation liquid chamber; 6011-Observation chamber; 6012-Inlet pipe; 6013-Outlet pipe; 6014-Pressure relief valve; 602-Fifth flow meter; 603-Main outlet valve. Detailed Implementation

[0028] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which constitute a part of the present invention and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0029] Example 1

[0030] A specific embodiment of the present invention, such as Figures 1-3 As shown, a precise dosing device for coal slime flotation reagents based on dual metering pumps is disclosed, including a first main pipeline 100, a first branch pipeline 200, a second branch pipeline 300, a first buffer pipeline 400, a second buffer pipeline 500, and a second main pipeline 600. The first branch pipeline 200 and the second branch pipeline 300 are connected in parallel, and the first buffer pipeline 400 and the second buffer pipeline 500 are also connected in parallel. The front end of the first branch pipeline 200 and the front end of the second branch pipeline 300 are simultaneously connected to the end of the first main pipeline 100. The end of the first branch pipeline 200 is connected to the front end of the first buffer pipeline 400, and the end of the second branch pipeline 300 is connected to the front end of the second buffer pipeline 500. The rear end of the first buffer pipeline 400 and the rear end of the second buffer pipeline 500 are simultaneously connected to the front end of the second main pipeline 600.

[0031] In this embodiment, the first branch 200 serves as a large-range coarse adjustment branch, and the second branch 300 serves as a small-range fine adjustment branch.

[0032] The first main pipeline 100 is equipped with a bag filter 101, a stop valve 102 and a Y-type filter 103. The bag filter 101, the stop valve 102 and the Y-type filter 103 are arranged in sequence according to the flow direction of the incoming material, that is, the incoming material passes through the bag filter 101, the stop valve 102 and the Y-type filter 103 in sequence.

[0033] In this embodiment, a bag filter 101 and a Y-type filter 103 are used for dual filtration of the pretreatment of the drug at the feed end to reduce impurities in the drug. Preferably, the filter screen size is 100 mesh.

[0034] The first branch 200 is equipped with a first check valve 201 and a first dosing pump 202, with the first dosing pump 202 located downstream of the first check valve 201.

[0035] Preferably, the first dosing pump 202 is a high-capacity mechanical diaphragm pump.

[0036] In this embodiment, the first branch 200 uses a mechanical diaphragm pump to add medicine, and the amount of medicine added is coarsely adjusted. The amount of medicine added is slightly less than the target amount (preferably, the difference from the target amount is 20-70% of the range of the small metering pump), and the difference between the amount of medicine added and the target amount is greater than the dosing error of the mechanical diaphragm pump.

[0037] For the safety of the first branch line 200, the first branch line 200 is also equipped with a first safety valve 203, which is located downstream of the first dosing pump 202.

[0038] Specifically, the first safety valve 203 is installed in the circuit, and the two ends of the circuit are connected to the two ends of the first dosing pump 202 through a guide pipe. When the outlet end of the first safety valve 203 is blocked and the pressure is too high, the first safety valve 203 opens, and the medicine flows back, ensuring system safety.

[0039] In order to obtain the pressure in the first branch 200, the first branch 200 is also provided with a first pressure gauge 204, which is located downstream of the first safety valve 203.

[0040] Considering the opening and closing of the first branch 200, the first branch 200 is also provided with a first switch valve 205, which is located at the end of the first branch 200, that is, at the connection position between the first branch 200 and the first buffer pipeline 400.

[0041] The first buffer pipeline 400 is equipped with a first buffer chamber 401, which is located downstream of the first switching valve 205. The front end of the first switching valve 205 is connected to the first dosing pump 202 via a guide pipe, and the rear end is connected to the first buffer chamber 401 via a guide pipe. When an abnormality occurs in the pipeline or when it is necessary to calibrate the safety pressure of the first safety valve 203, the valve of the first switching valve 205 is closed, and the pressure change of the first pressure gauge 204 is observed. The screw of the first safety valve 203 is then adjusted to control the safety pressure.

[0042] The first buffer pipeline 400 also includes a first damping pulsation damper 402, which is disposed on the first buffer chamber 401.

[0043] In order to obtain the flow rate of the agent in the first buffer pipeline 400, the first buffer pipeline 400 is also equipped with a first flow meter 403, which is located downstream of the first buffer chamber 401.

[0044] The first buffer pipeline 400 is also provided with a first back pressure valve 404, which is located downstream of the first flow meter 403.

[0045] In this embodiment, the first back pressure valve 404 is located at the drug outlet end. Its front end is connected to the first buffer chamber 401 through a guide pipe, and its rear end is connected to the drug outlet valve through a guide pipe. It maintains the pipeline outlet pressure to achieve positive pressure feeding, effectively preventing the drug from flowing back and flowing back due to fluctuations in the slurry flow field.

[0046] In this embodiment, to filter the mechanical pulsations caused by the mechanical diaphragm pump, reduce system pipeline vibration and noise, and stabilize the measurement environment, a first damping pulsation damper 402 is installed at the drug outlet end and connected to the first buffer chamber 401 via a guide pipe before the first back pressure valve 404. To ensure the stability of drug dispensing, the first buffer chamber 401 is connected to the first damping pulsation damper 402 via a guide pipe before the first back pressure valve 404. The front end of the first buffer chamber 401 is connected to the first safety valve 203 and the first dosing pump 202.

[0047] The first buffer line 400 is also equipped with a second flow meter 405, which is located downstream of the first back pressure valve 404.

[0048] The second branch 300 is equipped with a second check valve 301 and a second dosing pump 302, with the second dosing pump 302 located downstream of the second check valve 301.

[0049] Preferably, the second dosing pump 302 is a low-range mechanical diaphragm pump.

[0050] In this embodiment, the second branch 300 uses a small-range mechanical diaphragm pump for drug dosing. It is a closed-loop control system that finely adjusts the dosage. When the dosage is less than the target dosage, the dosing is precisely controlled to reach the target dosage.

[0051] For the safety of the second branch line 300, the second branch line 300 is also equipped with a second safety valve 303, which is located downstream of the second dosing pump 302.

[0052] Specifically, the second safety valve 303 is installed in the circuit, and the two ends of the circuit are connected to the two ends of the second dosing pump 302 through a guide pipe. When the outlet end of the second safety valve 303 is blocked and the pressure is too high, the second safety valve 303 opens, allowing the drug to flow back and ensuring system safety.

[0053] In order to obtain the pressure in the second branch 300, the second branch 300 is also provided with a second pressure gauge 304, which is located downstream of the second safety valve 303.

[0054] Considering the opening and closing of the second branch 300, the second branch 300 is also equipped with a second switching valve 305, which is located at the end of the second branch 300, that is, at the connection position between the second branch 300 and the second buffer pipeline 500.

[0055] The second buffer pipeline 500 is provided with a second buffer chamber 501, which is located downstream of the second switching valve 305. The front end of the second switching valve 305 is connected to the second dosing pump 302 through a guide pipe, and the rear end is connected to the second buffer chamber 501 through a guide pipe.

[0056] The second buffer pipeline 500 also includes a second damping pulsation damper 502, which is disposed on the second buffer chamber 501.

[0057] In order to obtain the flow rate of the agent in the second buffer pipeline 500, the second buffer pipeline 500 is also equipped with a third flow meter 503, which is located downstream of the second buffer chamber 501.

[0058] The second buffer line 500 is also equipped with a second back pressure valve 504, which is located downstream of the third flow meter 503.

[0059] In this embodiment, the second back pressure valve 504 is installed at the drug outlet end. Its front end is connected to the second buffer chamber 501 through a guide pipe, and its rear end is connected to the drug outlet valve through a guide pipe. It maintains the pipeline outlet pressure to achieve positive pressure feeding, effectively preventing the drug from flowing back and flowing back due to fluctuations in the slurry flow field.

[0060] In this embodiment, to filter the mechanical pulsations caused by the mechanical diaphragm pump, reduce system pipeline vibration and noise, and stabilize the measurement environment, a second damping pulsation damper 502 is installed at the drug outlet end and connected to the second buffer chamber 501 via a guide pipe before the second back pressure valve 504. To ensure the stability of drug dispensing, the second buffer chamber 501 is connected to the second damping pulsation damper 502 via a guide pipe before the second back pressure valve 504. The front end of the second buffer chamber 501 is connected to the second safety valve 303 and the second dosing pump 302.

[0061] The second buffer line 500 is also equipped with a fourth flow meter 505, which is located downstream of the second back pressure valve 504.

[0062] The second main pipeline 600 is provided with a buffer observation liquid tank 601 and a fifth flow meter 602. Preferably, the fifth flow meter 602 is located downstream of the buffer observation liquid tank 601.

[0063] Specifically, the buffer observation liquid tank 601 includes an observation tank 6011, a drug inlet pipe 6012, a drug outlet pipe 6013, and a pressure relief valve 6014. The observation tank 6011 has a gas cylinder-shaped structure. The drug inlet pipe 6012 is located at the top of the observation tank 6011 and communicates with the inner cavity of the observation tank 6011. The drug outlet pipe 6013 is located at the bottom of the observation tank 6011 and communicates with the inner cavity of the observation tank 6011. The pressure relief valve 6014 is located at the top of the observation tank 6011 and communicates with the inner cavity of the observation tank 6011. The pressure relief valve 6014 is located on one side of the drug inlet pipe 6012.

[0064] The observation chamber 6011 is placed vertically. The medicine enters from the top inlet end, passes through the inlet tube 6012, and flows freely or drips into the transparent observation chamber 6011. It then enters the outlet tube 6013 from the outlet at the bottom of the observation chamber 6011.

[0065] In this embodiment, the observation chamber 6011 is preferably made of PVC-U material, and the pressure relief valve 6014 is used to control the liquid level in the observation chamber 6011. This retains the traditional observation habits of chemical dosing workers, facilitating the observation of the free-flowing state of the chemical agent.

[0066] Example 2

[0067] Another specific embodiment of the present invention, such as Figure 4 As shown, a dosing control strategy based on dual metering pumps is disclosed. The coal slime flotation reagent precision dosing device of Example 1 is used. For the target dosing amount SP, the high-range metering pump (first dosing pump 202) is first controlled to reach 90% of the target dosing amount. Then, the low-range high-precision metering pump (second dosing pump 302) is used to compensate for the residual of the target dosing amount. The metering pump adopts a feedforward control method.

[0068] Furthermore, the feedforward control method refers to establishing a flow characteristic model of the pump based on pump characteristics and test calibration. The feedforward controller obtains the flow setting information and performs feedforward control on the high-range metering pump and the low-range metering pump according to the flow characteristic model. The resulting flow residual is used by the flow controller to finely adjust the low-range metering pump.

[0069] Specifically, the feedforward control method is as follows:

[0070] Step 1: Pump Flow Characteristic Curve Modeling: First, a model needs to be built based on the actual performance curve of the pump. A mathematical function fitting method is used to describe the relationship between the pump's flow rate and the control signal. For the flow characteristics of the mechanical diaphragm pump in this embodiment, the fitting equation is established as follows:

[0071]

[0072] Where Q is the pump flow rate, u is the pump control quantity (control frequency), and a, b, and c are the coefficients of the feedforward model to be fitted.

[0073] Step 2: Feedforward control of the high-range metering pump (first dosing pump 202): Based on the target dosing amount SP, first control the high-range metering pump (first dosing pump 202) to reach 90% of the target dosing amount. Assuming the control signal of the high-range metering pump is u1, feedforward control can be achieved through the following formula:

[0074]

[0075] Among them, f1 -1 It is the inverse function of the flow characteristic curve of a high-range metering pump.

[0076] Step 3: Compensation control of the low-range high-precision metering pump (second dosing pump 302): The residual error in the target dosing amount is compensated by the low-range high-precision metering pump (second dosing pump 302). Assuming the control signal of the low-range metering pump is u2, the compensation control can be achieved using the following formula:

[0077]

[0078] Where Q2 is the actual flow rate of the high-range metering pump after it reaches 90% of the target dosage, and f2 is the flow rate of the pesticide. -1 It is the inverse function of the flow characteristic curve of a low-range metering pump.

[0079] Step 4: Flow Controller Design: The flow controller finely adjusts the low-range metering pump to ensure that the error between the actual dosage and the target dosage is minimized. The specific design of the flow controller is determined based on the system's performance requirements and control strategy, employing a PID feedback control method.

[0080] This embodiment improves the accuracy of reagent dosing by using feedforward control of the high-range metering pump and compensation control of the low-range high-precision metering pump, thus ensuring the precision of the reagent dosage for coal slime flotation.

[0081] Example 3

[0082] Another specific embodiment of the present invention, such as Figures 1-4 As shown, a redundant flowmeter detection and verification method is disclosed, using the coal slime flotation reagent precision dosing device of Example 1. Flowmeter detection is divided into branch detection and total output detection. In flow detection, in the high-flow-rate branch (the branch connecting the first branch 200 and the first buffer pipe 400), one flowmeter (i.e., the first flowmeter 403 and the second flowmeter 405) is installed before and after the first back pressure valve 404 after the first buffer chamber 401. Similarly, in the low-flow-rate branch (the branch connecting the second branch 300 and the second buffer pipe 500), the flowmeters (i.e., the third flowmeter 503 and the fourth flowmeter 505) are also installed before and after the second back pressure valve 504. The total output flowmeter (i.e., the fifth flowmeter 602) is installed before the total output valve 603, after the two branches are merged.

[0083] In this embodiment, the first flow meter 403 in the main branch is positioned before the first back pressure valve 404 and after the first buffer chamber 401, while the third flow meter 503 in the small branch is positioned after the second buffer chamber 501. This significantly reduces the impact of airflow on flow meter detection, allowing for accurate measurement of the specific flow rate of the stable liquid in the buffer chamber and avoiding the influence of air within the system.

[0084] The flow meters before and after the first back pressure valve 404 and the second back pressure valve 504 are designed with redundancy and calibration, and the flow meters before and after them use different measurement principles. Preferably, the flow meter before the branch back pressure valve is a non-contact flow meter such as an ultrasonic flow meter, and the flow meter after the back pressure valve is a contact flow meter such as a gear flow meter.

[0085] Specifically, the redundant flow meter detection and calibration method includes branch calibration and total drug output calibration. If the sum of the branch flow rates is close to the total drug output, the flow meter detection is considered to be relatively accurate and can be used as feedback information. For the high-range branch in the branch calibration, the flow meters installed before and after the branch outlet back pressure valve (first back pressure valve 404) are denoted as HF1 and HF2, respectively. HF1 is in the pipeline pulse segment, and HF2 is in the flow stability segment. Based on the high-range metering pump operating cycle HT1, similarly, the low-range branch flow meters LF1 and LF2 and the low-range metering pump operating cycle LT1 are obtained. During operation, since the operating frequencies of the two branch pumps are different, in order to achieve cycle matching calibration, the calibration sampling period is n*HT1*LT1, where n = 1, 2, 3... (for cases where the operating frequencies of the two branch pumps are similar, the value of n is small; for cases where the operating frequencies of the two branch pumps differ significantly, the value of n is large), thereby mitigating the influence of pipeline pulses. In addition, the integral values ​​of the flow rates of HF1 and HF2 over the time interval 2T1 are compared. If... This indicates that there may be a problem with the pipeline damping system, and it is necessary to: 1) check for pipeline blockage;

[0086] 2) Check the air pressure of the first damping pulsation shock absorber 402, the pressure setting range of the first back pressure valve 404 and the first safety valve 203. The specific steps are as follows:

[0087] I. Check whether the pre-charge pressure of the first damping pulsation damper 402 is within the normal range. For a general flotation dosing system, the pressure range of the first damping pulsation damper 402 is 0.05-0.15 MPa.

[0088] II. Check the pressure setting value of the first back pressure valve 404. The pressure value of the first damping pulsation damper 402 should be 50%-80% of the pressure setting value of the first back pressure valve. Since the first damping pulsation damper 402 is installed at the pump outlet in this system, the pressure value of the first damping pulsation damper 402 should preferably be 50% of the pressure setting value of the first back pressure valve 404.

[0089] III. Check the pressure setting value of the first safety valve 203. In this embodiment, the pressure setting value of the first safety valve 203 should be 2-3 times the pressure setting value of the first back pressure valve 404.

[0090] IV. When the first metering pump 202 is working, observe the pressure gauge pointer at the top of the first damping pulsation shock absorber 402. During use, the pressure gauge pointer should swing slightly. If the swing is too large, it indicates that the pre-charge gas pressure is too low or the model is too small. If there is no swing, it indicates that the pre-charge gas pressure is too high or the pipeline is blocked.

[0091] Similarly, for low-range branches, if The pipeline damping system needs to be checked (same as above, corresponding to the components in the low-range branch).

[0092] For total quantity verification, record the outlet total flow meter TL1, if the current... Then the pipeline instruments need to be calibrated. Since the flow meter LH2 in the small-range branch of the pipeline system has the highest accuracy, by keeping the flow rate of the high-range branch unchanged and increasing the flow rate of the small-range branch, the total flow meter TL1 can be calibrated to a certain extent.

[0093] This embodiment achieves precise dosing control of flotation reagents through multi-flow meter detection and verification. The actual flow rate is verified by the branch flow meter and the total reagent flow meter, and then feedback control is implemented to accurately control the dosing amount.

[0094] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A dosing control method based on dual metering pumps, characterized in that, A precise dosing device for coal slime flotation reagents is adopted, and the metering pump uses a feedforward control method, including the following steps: Step 1: Pump flow characteristic curve modeling; a model is created based on the actual performance curve of the pump, and a mathematical function fitting method is used to describe the relationship between the pump flow rate and the control signal; Step 2: Feedforward control of the high-range metering pump; based on the target dosing quantity SP, the first dosing pump is first controlled to reach 90% of the target dosing quantity; Step 3: Compensation control of the low-range high-precision metering pump; for the residual of the target dosing quantity, compensation is performed through the second dosing pump; Step 4: The flow controller performs fine adjustment of the low-range metering pump to ensure that the error between the actual dosing quantity and the target dosing quantity is minimized; The precise dosing device for coal slime flotation reagents includes a first main pipeline, a first branch pipeline, a second branch pipeline, a first buffer pipeline, a second buffer pipeline, and a second main pipeline. The first branch pipeline and the second branch pipeline are connected in parallel, as are the first buffer pipeline and the second buffer pipeline. The front ends of the first branch pipeline and the second branch pipeline are simultaneously connected to the end of the first main pipeline. The end of the first branch pipeline is connected to the front end of the first buffer pipeline, and the end of the second branch pipeline is connected to the front end of the second buffer pipeline. The rear ends of the first buffer pipeline and the rear ends of the second buffer pipeline are simultaneously connected to the front end of the second main pipeline. The first dosing pump is a high-capacity mechanical diaphragm pump, and the first branch pipeline uses a high-capacity mechanical diaphragm pump for coarse adjustment of the dosing amount. The second dosing pump is a low-capacity mechanical diaphragm pump, and the second branch pipeline uses a low-capacity mechanical diaphragm pump for closed-loop control, allowing for fine adjustment of the dosing amount. For total quantity verification, record the outlet total flow meter TL1, if the current... Then, the pipeline instruments need to be calibrated. Specifically, the flow meter installed after the back pressure valve at the outlet of the high-range branch is designated HF2, the operating cycle of the high-range metering pump is designated HT1, the flow meter of the low-range branch is designated LF2, the operating cycle of the low-range metering pump is designated LT1, and the verification sampling cycle is n. HT1 LT1, n = 1, 2, 3...; The second main pipeline is equipped with a buffer observation liquid tank and a fifth flow meter. The buffer observation liquid tank includes an observation tank, an inlet pipe, an outlet pipe, and a pressure relief valve. The observation tank has a gas cylinder-shaped structure. The medicine enters from the upper inlet end, passes through the inlet pipe, and flows freely or drips into the transparent observation tank. It enters the outlet pipe from the bottom outlet of the observation tank. The pressure relief valve is used to control the liquid level in the observation tank.

2. The dosing control method based on dual metering pumps according to claim 1, characterized in that, The first main pipeline is equipped with a bag filter, a shut-off valve, and a Y-type filter.

3. The dosing control method based on dual metering pumps according to claim 1, characterized in that, The first branch is equipped with a first check valve and a first dosing pump, with the first dosing pump located downstream of the first check valve.

4. The dosing control method based on dual metering pumps according to claim 3, characterized in that, The first branch is also equipped with a first pressure gauge.

5. The dosing control method based on dual metering pumps according to claim 3, characterized in that, The first branch is also equipped with a first switching valve.

6. The dosing control method based on dual metering pumps according to any one of claims 1-5, characterized in that, The second branch is equipped with a second check valve and a second dosing pump, with the second dosing pump located downstream of the second check valve.

7. The dosing control method based on dual metering pumps according to claim 6, characterized in that, The second branch is also equipped with a second pressure gauge and a second switching valve.

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