Dosing control method for coal slime flotation

Abstract

This invention relates to a reagent dosing control method for coal slime flotation, belonging to the field of coal sorting and processing technology. It solves the problem of poor control accuracy in existing coal slime flotation reagent dosing flow control methods. The reagent dosing control method includes: Step S1: Determining the initial reagent flow rate pumped into the reagent tank, ensuring the reagent level in the tank reaches the target height; Step S2: Determining the initial needle valve opening for each flotation cell, starting reagent dosing, and obtaining the actual reagent flow rate for each flotation cell during the dosing process; Step S3: Adjusting the needle valve opening for each flotation cell, ensuring the actual reagent flow rate and preset reagent flow rate meet the flow error threshold; Step S4: Obtaining the actual reagent level in the reagent tank during dosing, and adjusting the reagent flow rate pumped into the tank based on the target level, ensuring the reagent level in the tank remains stable at the target level. This achieves precise control of the reagent dosing flow rate for multiple flotation cells during the dosing process.

Description

Technical Field

[0001] This invention relates to the field of coal sorting and processing technology, and in particular to a method for controlling the addition of reagents in coal slime flotation. Background Technology

[0002] Coal slime flotation is an important part of coal preparation production, and the method and accuracy of reagent addition in flotation are important factors affecting the flotation effect.

[0003] Coal slime flotation requires reagent addition at very low flow rates. Currently, commonly used reagent control methods both domestically and internationally often result in low precision in controlling these low flow rates. Furthermore, unstable feed pressure during dosing prevents the reagents from fully mixing with the slurry in the flotation cell. The added reagents are easily carried away by overflowing foam, leading to poor slurry mineralization and low impurity removal efficiency. This makes even coal preparation plants with automated flotation reagent control less than ideal in terms of overall control performance.

[0004] Therefore, there is an urgent need for a technical solution that can control the precise addition of reagents during the coal slime flotation process. Summary of the Invention

[0005] Based on the above analysis, the embodiments of the present invention aim to provide a dosing control method for coal slime flotation, in order to solve the problem of poor control accuracy in the existing coal slime flotation dosing flow control method.

[0006] This invention provides a dosing control method for coal slime flotation, the dosing control method comprising:

[0007] Step S1: Determine the initial reagent flow rate pumped into the storage tank based on the preset reagent flow rates of multiple flotation cells, so that the reagent level in the storage tank reaches the target height;

[0008] Step S2: Determine the initial needle valve opening for each flotation cell based on the preset reagent flow rate and the corresponding flow interaction model of multiple flotation cells, start adding reagents, and obtain the actual reagent flow rate of each flotation cell during the adding process;

[0009] Step S3: Adjust the needle valve opening of each flotation cell according to the actual reagent flow rate and the preset reagent flow rate of the corresponding flotation cell during the dosing process, so that the actual reagent flow rate and the preset reagent flow rate of each flotation cell meet the flow error threshold.

[0010] Step S4: Obtain the actual height of the medicine in the storage tank during the dosing process, and adjust the flow rate of the medicine pumped into the storage tank according to the target height so that the height of the medicine in the storage tank is stable at the target height.

[0011] Based on the further improvement of the above dosing control method, in step S3, the needle valve opening of each flotation cell is adjusted according to the following formula:

[0012]

[0013] Where, μ n (t) represents the needle valve opening of the nth flotation cell after adjustment, L n K represents the preset reagent flow rate of the nth flotation cell, N represents the number of flotation cells, and K represents the number of flotation cells. Lp L represents the flow proportional gain coefficient. no (t) represents the actual reagent flow rate in the nth flotation cell, K Li denoted as the flow integral gain coefficient, t represents any time, and τ represents the integral variable, with values ​​ranging from 0 to t.

[0014] Based on the further improvement of the above-mentioned dosing control method, in step S4, the flow rate of the agent pumped into the storage tank is adjusted according to the following formula:

[0015]

[0016] Where L'(t) represents the adjusted flow rate of the drug pumped into the storage tank, and K Hp The height proportional gain coefficient is represented by H, the target height is represented by H(t), and the actual height of the medicine in the storage tank is represented by K. Hi This represents the integral gain coefficient.

[0017] Based on further improvements to the above-mentioned dosing control method, the flow interaction model is determined through the following steps:

[0018] Adjust the needle valve opening of each flotation cell from fully closed to fully open, so that the needle valve opening of each flotation cell traverses all needle valve opening combinations, and obtain the reagent flow data of each flotation cell under each needle valve combination;

[0019] The relationship between the reagent flow rate of all flotation cells and the needle valve opening of all flotation cells is obtained by fitting the reagent flow rate data, which serves as the flow interaction model.

[0020] Based on the further improvement of the above-mentioned dosing control method, during the dosing process, the agent is made to enter the storage tank through the inlet port by the dosing device;

[0021] The reagents are directed to multiple flotation cells through the dispensing device. The bottom of the reagent storage tank has two ports, which serve as the inlet and outlet ports, respectively.

[0022] Based on a further improvement of the above-mentioned dosing control method, the dosing device includes a dosing pipeline, and a first valve switch, a check valve and a mechanical diaphragm pump sequentially arranged in the dosing pipeline;

[0023] One end of the drug inlet pipe is connected to the drug inlet port, and the other end serves as the drug entry point;

[0024] The medicine flows to the input end of the check valve under the control of the first valve switch. The check valve is used to control the flow direction of the medicine.

[0025] The medicine flows from the output end of the one-way valve to the input end of the mechanical diaphragm pump;

[0026] Mechanical diaphragm pumps are used to pump medicines into the storage tank through the inlet port.

[0027] Based on further improvements to the above-mentioned dosing control method, a back pressure valve and a first filter are also installed on the dosing pipeline;

[0028] The input end of the back pressure valve is connected to both the drug inlet port and the output end of the mechanical diaphragm pump, and the output end of the back pressure valve is connected to both the output end of the check valve and the input end of the mechanical diaphragm pump.

[0029] The first filter is located between the first valve switch and the check valve.

[0030] Based on a further improvement of the above-mentioned dosing control method, the dosing device includes multiple first dosing branches, the input end of each first dosing branch is connected to the dosing port, and the output end of each first dosing branch is connected to the corresponding flotation cell.

[0031] Each of the first drug dispensing branches is sequentially equipped with a second valve switch, a first toothed flow meter, and a first electric needle valve;

[0032] The first circular tooth flow meter is used to measure the flow rate of the reagent entering the first discharge branch, and the first electric needle valve controls the flow rate of the reagent entering the flotation cell.

[0033] Based on a further improvement of the above-mentioned dosing control method, the dosing device includes a main channel, a plurality of third valve switches arranged sequentially on the main channel, and a second dosing branch with the same number of third valve switches.

[0034] The main channel is connected to the drug outlet port;

[0035] The input terminal of each second drug dispensing branch is connected to the output terminal of the corresponding third valve switch on the main road;

[0036] Each third outlet branch is equipped with a second toothed flow meter and a second electric needle valve. The second toothed flow meter is used to measure the flow rate of the reagent entering the corresponding third outlet branch, and the second electric needle valve controls the flow rate of the reagent entering the flotation cell.

[0037] Based on further improvements to the above-mentioned dosing control method, a second filter is also installed on the main channel;

[0038] The second filter is installed between the drug outlet port and the first third valve switch.

[0039] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0040] 1. During the dosing process, the needle valve opening of each flotation cell is adjusted according to the actual reagent flow rate and the preset reagent flow rate of each flotation cell. This ensures that the reagent flow rate entering multiple flotation cells meets the preset flow rate requirements of each flotation cell, improving the accuracy of flow control. At the same time, the reagent level in the storage tank is kept stable during the dosing process, allowing the reagent added to the flotation cell to be fully mixed with the slurry, resulting in good mineralization effect.

[0041] 2. During the dosing process, adjust the needle valve opening of each flotation cell according to the actual reagent flow rate and preset reagent flow rate of each flotation cell after the last adjustment. When adjusting, add a proportional coefficient before the flow rate proportional gain coefficient of each flotation cell in combination with the preset reagent flow rate of all flotation cells, so that when multiple flotation cells are adjusted together, they can enter the stable stage at the same time, and the actual reagent flow rate obtained by each flotation cell can simultaneously meet the preset reagent flow rate.

[0042] 3. By determining the initial needle valve opening of each flotation cell at the start of the dosing process as feedforward control, and combining this with adjusting the needle valve opening of the corresponding flotation cell according to the actual reagent flow rate and the preset reagent flow rate during the dosing process as feedback control, the reagent flow rate added to each flotation cell can meet the preset flow rate requirements of each flotation cell as much as possible, thus further improving the dosing accuracy.

[0043] 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

[0044] 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.

[0045] Figure 1 A schematic flowchart of a reagent control method for coal slime flotation provided in an embodiment of the present invention;

[0046] Figure 2 This is a schematic diagram of the structure for implementing a reagent control method for coal slime flotation according to an embodiment of the present invention. Detailed Implementation

[0047] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of this application 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.

[0048] A specific embodiment of the present invention discloses a method for controlling reagent dosing in coal slime flotation, such as... Figure 1 As shown, the dosing control method includes:

[0049] Step S1: Determine the initial reagent flow rate pumped into the storage tank based on the preset reagent flow rates of multiple flotation cells, so that the reagent level in the storage tank reaches the target height;

[0050] Step S2: Determine the initial needle valve opening for each flotation cell based on the preset reagent flow rate and the corresponding flow interaction model of multiple flotation cells, start adding reagents, and obtain the actual reagent flow rate of each flotation cell during the adding process;

[0051] Step S3: Adjust the needle valve opening of each flotation cell according to the actual reagent flow rate and the preset reagent flow rate of the corresponding flotation cell during the dosing process, so that the actual reagent flow rate and the preset reagent flow rate of each flotation cell meet the flow error threshold.

[0052] Step S4: Obtain the actual height of the medicine in the storage tank during the dosing process, and adjust the flow rate of the medicine pumped into the storage tank according to the target height so that the height of the medicine in the storage tank is stable at the target height.

[0053] Specifically, the coal slime flotation process includes two main stages: before and during the reagent addition process. For example... Figure 1 As shown, step S1 is the preparation work before the start of the dosing process. After determining the initial needle valve opening of each flotation cell in step S2, the dosing process can begin. During the dosing process, the actual reagent flow rate of each flotation cell is measured and obtained. Steps S3 and S4 are both dosing processes. During the dosing process, the actual reagent flow rate of each flotation cell is kept within the flow error threshold between the actual reagent flow rate and the preset reagent flow rate to achieve precise dosing of each flotation cell and to keep the reagent height in the storage tank stable at the target height, so that the dosing pressure is stable and the reagent can fully mix and react with the slurry after entering the flotation cell.

[0054] Specifically, such as Figure 1As shown, in step S1, the preset flow rate of reagent in each flotation cell can be reasonably set according to actual conditions; it can be the same or different. During the dosing process, it is not limited to a single flotation cell; multiple flotation cells can be dosed simultaneously, making it widely applicable and suitable for coal slime flotation in various scenarios. The reagent storage tank serves as a transfer station for storing reagents and also provides the power source for dosing. Before the dosing process begins, the reagent needs to be pumped into the storage tank, and the target height of the reagent in the storage tank is determined in advance.

[0055] Specifically, in step S1, after determining the preset reagent flow rates of multiple flotation cells, the reagent flow rate that needs to be continuously pumped into the storage tank during the dosing process can be determined. The sum of the preset reagent flow rates of multiple flotation cells is used as the initial reagent flow rate pumped into the storage tank. This allows for minimizing large changes in the reagent flow rate pumped into the storage tank during the formal dosing process, making the adjustment more gradual and natural. At the same time, it also allows the reagent flow rate pumped into the storage tank to serve as feedforward control to maintain the reagent level in the storage tank.

[0056] Specifically, such as Figure 1 As shown, in step S2, after the reagent level in the storage tank reaches the target level, the initial needle valve opening for each flotation cell is adjusted. It can be understood that the needle valve opening for each flotation cell corresponds to the flow rate of reagent added to that cell. The initial needle valve opening for each flotation cell is determined based on the preset reagent flow rate and a pre-constructed flow interaction model, thus determining the approximate range of reagent flow rate added to each flotation cell. This range has a slight error compared to the preset reagent flow rate, serving as feedforward control.

[0057] Specifically, in step S2, the initial needle valve opening of each flotation cell is adjusted. Under the action of the reagent at the target height in the reagent tank, the reagent enters the flotation cell through the needle valve of each flotation cell for mixing and reaction. The actual reagent flow rate added to each flotation cell during the dosing process is measured and obtained.

[0058] Specifically, steps S3 and S4 are both stages of the reagent dosing process. During this stage, it is necessary to ensure that the error between the actual reagent flow rate and the preset reagent flow rate in each flotation cell always meets the flow error threshold. The flow error threshold can be reasonably set in advance according to specific circumstances, so that the reagent dosing control method can be reasonably set according to different slurries and has a wide range of applications.

[0059] Specifically, in step S3, the opening of the needle valve in each flotation cell is adjusted to change the actual reagent flow rate entering each flotation cell, thereby making the actual reagent flow rate as close as possible to the preset reagent flow rate. It is worth noting that the needle valve opening of each flotation cell is adjusted by comparing the actual reagent flow rate with the preset reagent flow rate during the dosing process.

[0060] Preferably, in step S3, the needle valve opening of each flotation cell is adjusted according to the following formula:

[0061]

[0062] Where, μ n (t) represents the needle valve opening of the nth flotation cell after adjustment, L n K represents the preset reagent flow rate of the nth flotation cell, N represents the number of flotation cells, and K represents the number of flotation cells. Lp L represents the flow proportional gain coefficient. no (t) represents the actual reagent flow rate in the nth flotation cell, K Li denoted as the flow integral gain coefficient, t represents any time, and τ represents the integral variable, with values ​​ranging from 0 to t.

[0063] Specifically, the required needle valve opening for each adjustment can be determined using the formula described above for adjusting the needle valve opening of each flotation cell. It is understood that determining the required needle valve opening for the next adjustment requires calculation based on the actual reagent flow rate after the previous adjustment and the preset reagent flow rate.

[0064] It is worth noting that the flow rate proportional gain coefficient for each flotation cell is set to be the same. At the same time, a proportional coefficient is further added in front of the flow rate proportional gain coefficient according to the preset reagent flow rate of each flotation cell, so that when multiple flotation cells are adjusted together, they can enter the stable stage at the same time, and the actual reagent flow rate obtained by each flotation cell can simultaneously meet the preset reagent flow rate.

[0065] Specifically, such as Figure 1 As shown, in step S4, the actual height of the pesticide in the storage tank during the dosing process is obtained, and the flow rate of the pesticide pumped into the storage tank is adjusted based on the target height to stabilize the pesticide height in the storage tank at the target height. It is understandable that during the dosing process, the flow rate of the pesticide pumped into and out of the storage tank changes, thus affecting the pesticide height in the storage tank. To stabilize the pressure of the pesticide flowing out of the storage tank, the pesticide height in the storage tank must be stabilized at the target height.

[0066] Preferably, in step S4, the flow rate of the medicine pumped into the storage tank is adjusted according to the following formula:

[0067]

[0068] Where L'(t) represents the adjusted flow rate of the drug pumped into the storage tank, and K Hp The height proportional gain coefficient is represented by H, the target height is represented by H(t), and the actual height of the medicine in the storage tank is represented by K. HiThis represents the integral gain coefficient.

[0069] Specifically, the target height, height proportional gain coefficient, and height integral gain coefficient are all pre-set parameters.

[0070] Specifically, a suitable gain coefficient can be obtained through multiple experiments.

[0071] During the dosing process, the flow rate of the agent pumped into the storage tank is determined based on the actual height and target height at the previous adjustment, so that the agent height in the storage tank is stabilized at the target height.

[0072] Preferably, during the dosing process, the agent is fed into the storage tank through the inlet port by the dosing device;

[0073] The reagents are directed to multiple flotation cells through the dispensing device. The bottom of the reagent storage tank has two ports, which serve as the inlet and outlet ports, respectively.

[0074] Specifically, such as Figure 2 As shown, during the dosing process, the high stability of the reagent in the storage tank can stabilize the pressure of the reagent entering the flotation cell, improve the mixing degree of the reagent with the slurry in each flotation cell, and reduce the amount of reagent carried out with the foam.

[0075] Specifically, such as Figure 2 As shown, the drug feeding device includes a drug feeding pipeline, and a first valve switch, a check valve and a mechanical diaphragm pump sequentially arranged in the drug feeding pipeline;

[0076] One end of the drug inlet pipe is connected to the drug inlet port, and the other end serves as the drug entry point;

[0077] The medicine flows to the input end of the check valve under the control of the first valve switch. The check valve is used to control the flow direction of the medicine.

[0078] The medicine flows from the output end of the one-way valve to the input end of the mechanical diaphragm pump;

[0079] Mechanical diaphragm pumps are used to pump medicines into the storage tank through the inlet port.

[0080] Preferably, the drug inlet pipe is further equipped with a back pressure valve and a first filter;

[0081] The input end of the back pressure valve is connected to both the drug inlet port and the output end of the mechanical diaphragm pump, and the output end of the back pressure valve is connected to both the output end of the check valve and the input end of the mechanical diaphragm pump.

[0082] The first filter is located between the first valve switch and the check valve.

[0083] Specifically, such as Figure 2As shown, the medicine enters the inlet device from the inlet end and passes sequentially through the first valve switch, the first filter, the one-way valve and the mechanical diaphragm pump installed on the inlet pipeline. The mechanical diaphragm pump pumps the medicine through the inlet port into the storage tank for storage.

[0084] Specifically, the first valve switch is used to control whether to add medicine, and the first filter is used to filter the medicine for the first time, which plays a role in pre-removing impurities. Preferably, the first filter is a Y-type filter.

[0085] Specifically, under the control of the check valve, the medicine can only enter the mechanical diaphragm pump from the top. As the mechanical diaphragm pump works, the medicine enters the inlet port, effectively preventing backflow of the medicine.

[0086] Specifically, by adjusting the motor speed of the mechanical diaphragm pump, the flow rate of the medicine in the inlet pipe can be adjusted, thereby controlling the flow rate of the medicine pumped into the storage tank.

[0087] Specifically, when the dispensing device in the medicine storage tank becomes clogged, it will cause excessive pressure in the lower medicine inlet pipe. To prevent damage to the medicine inlet pipe, a back pressure valve can be installed to effectively reduce the pressure in the lower medicine inlet pipe. It is worth noting that the back pressure valve can only allow unidirectional flow, that is, flow can only be from top to bottom, and cannot flow in the opposite direction.

[0088] In one embodiment, the dispensing device includes a plurality of first dispensing branches, the input end of each first dispensing branch being connected to a dispensing port, and the output end of each first dispensing branch being connected to a corresponding flotation cell;

[0089] Each of the first drug dispensing branches is sequentially equipped with a second valve switch, a first toothed flow meter, and a first electric needle valve;

[0090] The first circular tooth flow meter is used to measure the flow rate of the reagent entering the first discharge branch, and the first electric needle valve controls the flow rate of the reagent entering the flotation cell.

[0091] Specifically, the input end of each first reagent outlet branch is connected to the reagent outlet port, which allows the reagent flow from the reagent outlet port to flow evenly to different flotation cells. This enables quick and convenient addition of reagents to multiple flotation cells with the same preset reagent flow rate, ensuring thorough mixing of the reagents with the slurry in the flotation cells.

[0092] Specifically, the second valve switch, the first toothed flow meter, and the first electric needle valve, which are sequentially installed on the first drug outlet branch, can effectively control, measure, and adjust the drug flow rate entering the first drug outlet branch.

[0093] In another embodiment, the dispensing device includes a main channel, a plurality of third valve switches arranged sequentially on the main channel, and a second dispensing branch with the same number of third valve switches;

[0094] The main channel is connected to the drug outlet port;

[0095] The input terminal of each second drug dispensing branch is connected to the output terminal of the corresponding third valve switch on the main road;

[0096] Each third outlet branch is equipped with a second toothed flow meter and a second electric needle valve. The second toothed flow meter is used to measure the flow rate of the reagent entering the corresponding third outlet branch, and the second electric needle valve controls the flow rate of the reagent entering the flotation cell.

[0097] Preferably, a second filter is also provided on the main road;

[0098] The second filter is installed between the drug outlet port and the first third valve switch.

[0099] Specifically, such as Figure 2 As shown, multiple third valve switches are sequentially installed on the main channel of the dispensing device, as well as the same number of second dispensing branches. The dispensing port is connected to the main channel, allowing the reagent in the storage tank to flow to the main channel. The main channel distributes the reagent to different second dispensing branches through the third valve switches. On each second dispensing branch, the reagent sequentially passes through a second circular tooth flow meter and a second electric needle valve into the flotation cell.

[0100] Specifically, such as Figure 2 As shown, a second filter is also installed on the main channel. The second filter is used for post-filtering. The mesh number of the filter is higher than that of the first filter, which can effectively prevent the medicine flowing out from the medicine outlet from clogging the second electric needle valve and the second toothed flow meter.

[0101] It is worth noting that, such as Figure 2 As shown, the storage tank is placed at a high position, and the reagent is continuously pumped into the storage tank through the feeding device. When the reagent needs to be added, the reagent is then discharged to each flotation cell by gravity through the discharging device.

[0102] Preferably, each second electric needle valve is set at the same height, which improves the coordination between different electric needle valves and increases the stability of drug flow regulation.

[0103] Specifically, a first filter and a second filter are installed in the drug inlet and drug outlet devices, respectively, to remove impurities from the drug through dual filtration.

[0104] Specifically, when the dosing process begins, the initial opening of the second electric needle valve is determined based on the preset reagent flow rate of each flotation cell and the corresponding flow interaction model, and the initial actual reagent flow rate of each flotation cell is measured and obtained.

[0105] During the dosing process, the actual reagent flow rate of each flotation cell is measured by the second circular tooth flow meter. Based on the comparison between the actual reagent flow rate and the preset reagent flow rate, the opening of the second electric needle valve is adjusted until the actual reagent flow rate and the preset reagent flow rate meet the flow error threshold.

[0106] It is worth noting that the target height can be determined based on the maximum chemical flow rate of the dosing facility. Specifically, for example... Figure 2 As shown, when all the second electric needle valves are opened to their maximum extent, the cross-sectional area through which the drug flows is maximized. Once the maximum drug flow rate of the dosing mechanism is known, the speed of the drug flow can be calculated. This speed is directly proportional to the height of the drug in the storage tank; that is, the higher the height of the drug in the storage tank, the greater the speed. Thus, the drug height that satisfies the maximum drug flow rate can be determined, and this height can be set in advance as the target height.

[0107] Specifically, before the dosing process begins, the initial motor speed of the mechanical diaphragm pump is determined based on the preset reagent flow rate of each flotation cell, so that the reagent level in the storage tank reaches the target height.

[0108] During the dosing process, the motor speed of the mechanical diaphragm pump is adjusted according to the target height and the actual height of the storage tank to keep the actual height of the storage tank stable at the target height.

[0109] Specifically, a level gauge can be installed in the medicine storage tank to measure the actual height of the medicine in the tank in real time.

[0110] Preferably, such as Figure 2 As shown, a pressure gauge can also be installed at the drug outlet port, and the actual height of the drug in the storage tank can be determined by the pressure gauge.

[0111] Specifically, such as Figure 2 As shown, before the dosing process begins, the reagent is pumped into the storage tank through the feeding device to bring the reagent level in the storage tank to the target height. When the dosing process begins, the reagent enters multiple flotation cells through the discharging device under the action of gravity.

[0112] Specifically, during the dosing process, it is necessary to maintain the drug level in the storage tank at the target level. This requires continuously pumping the drug into the storage tank through the drug feeding device.

[0113] It is worth noting that the embodiments of the present invention utilize the predictive capability of feedforward control and the adjustment capability of feedback control. In particular, when the flow demand changes dynamically, it achieves coordinated control of reagent flow, avoids interference and conflict, ensures the actual reagent flow of each flotation cell, meets the preset reagent flow of the corresponding flotation cell, and improves the dosing accuracy by stabilizing the reagent height in the storage tank at the target height.

[0114] Preferably, the traffic interaction model is determined through the following steps:

[0115] Adjust the needle valve opening of each flotation cell from fully closed to fully open, so that the needle valve opening of each flotation cell traverses all needle valve opening combinations, and obtain the reagent flow data of each flotation cell under each needle valve combination;

[0116] The relationship between the reagent flow rate of all flotation cells and the needle valve opening of all flotation cells is obtained by fitting the reagent flow rate data, which serves as the flow interaction model.

[0117] Specifically, the opening degree of each second electric needle valve is determined, from fully closed to fully open. For example, the opening degree of fully closed is 0 and the opening degree of fully open is 9. Then, each second electric needle valve includes 10 opening degrees from fully closed to fully open. If 3 flotation cells are simultaneously dosing chemicals, then there are 1000 opening degree combinations for the 3 second electric needle valves. If more flotation cells are simultaneously dosing chemicals, there will be even more opening degree combinations.

[0118] It is worth noting that several opening combinations can be selected from all possible combinations to conduct experiments and obtain the opening of the second electric needle valve and the reagent flow rate data of each flotation cell under these combinations. By fitting the reagent flow rate data, the correspondence between the opening of all second electric needle valves and the reagent flow rate of all flotation cells can be obtained, serving as a flow interaction model.

[0119] Specifically, in the flow interaction model, each opening combination corresponds to a preset reagent flow rate for each flotation cell. After fitting, the preset reagent flow rates of all flotation cells can also correspond to the opening of the second electric needle valve.

[0120] Compared with existing technologies, the present invention provides a reagent control method for coal slime flotation. During reagent dosing, the opening of the needle valve in each flotation cell is adjusted based on the actual and preset reagent flow rates. This ensures that the reagent flow rate entering multiple flotation cells meets the preset flow rate requirements of each cell, improving the accuracy of flow control. Simultaneously, the reagent level in the storage tank is maintained stably during dosing, allowing the reagent added to the flotation cells to mix thoroughly with the slurry, resulting in good mineralization. Furthermore, during dosing, the needle valve opening of each flotation cell is adjusted based on the actual and preset reagent flow rates after the previous adjustment. By adding a proportional coefficient before the flow proportional gain coefficient of each flotation cell, based on the preset reagent flow rates of all flotation cells, multiple flotation cells can simultaneously enter the stable phase when adjusted together, and the actual reagent flow rate obtained by each flotation cell can simultaneously meet the preset reagent flow rate. Simultaneously, by determining the initial needle valve opening of each flotation cell at the start of the dosing process as feedforward control, and combining this with adjusting the needle valve opening of the corresponding flotation cell according to the actual and preset reagent flow rates during the dosing process as feedback control, the reagent flow rate added to each flotation cell is made to meet the preset flow rate requirements of each flotation cell as much as possible, further improving the dosing accuracy.

[0121] 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 method for controlling reagent dosing in coal slime flotation, characterized in that, The dosing control method includes: Step S1: Determine the initial reagent flow rate pumped into the storage tank based on the preset reagent flow rates of multiple flotation cells, so that the reagent level in the storage tank reaches the target height; Step S2: Determine the initial needle valve opening for each flotation cell based on the preset reagent flow rate and the corresponding flow interaction model of multiple flotation cells, start adding reagents, and obtain the actual reagent flow rate of each flotation cell during the adding process; Step S3: Adjust the needle valve opening of each flotation cell according to the actual reagent flow rate and the preset reagent flow rate of the corresponding flotation cell during the dosing process, so that the actual reagent flow rate and the preset reagent flow rate of each flotation cell meet the flow error threshold. Step S4: Obtain the actual height of the medicine in the storage tank during the dosing process, and adjust the flow rate of the medicine pumped into the storage tank according to the target height so that the height of the medicine in the storage tank is stable at the target height; In step S3, the needle valve opening of each flotation cell is adjusted according to the following formula: ； in, Indicates the adjusted number The opening degree of the needle valve in each flotation cell Indicates the first The preset reagent flow rate for each flotation cell Indicates the number of flotation cells. This represents the flow rate proportional gain coefficient. Indicates the first The actual reagent flow rate of each flotation cell Represents the integral gain coefficient of flow rate. Represents any time. Represents the integral variable, with values ​​ranging from 0 to... ; In step S4, the flow rate of the medicine pumped into the storage tank is adjusted according to the following formula: ； in, This indicates the adjusted flow rate of the medicine pumped into the storage tank. Indicates the height proportional gain coefficient. Indicates the target height. This indicates the actual height of the medicine in the medicine storage box. This represents the integral gain coefficient.

2. The dosing control method according to claim 1, characterized in that, The traffic interaction model is determined through the following steps: Adjust the needle valve opening of each flotation cell from fully closed to fully open, so that the needle valve opening of each flotation cell traverses all needle valve opening combinations, and obtain the reagent flow data of each flotation cell under each needle valve combination; The relationship between the reagent flow rate of all flotation cells and the needle valve opening of all flotation cells is obtained by fitting the reagent flow rate data, which serves as the flow interaction model.

3. The dosing control method according to claim 1, characterized in that, During the dosing process, the medicine is fed into the storage tank through the inlet port via the dosing device; The reagents are directed to multiple flotation cells through the dispensing device. The bottom of the reagent storage tank has two ports, which serve as the inlet and outlet ports, respectively.

4. The dosing control method according to claim 3, characterized in that, The drug feeding device includes a drug feeding pipeline, and a first valve switch, a check valve and a mechanical diaphragm pump arranged sequentially in the drug feeding pipeline; One end of the drug inlet pipe is connected to the drug inlet port, and the other end serves as the drug entry point; The medicine flows to the input end of the check valve under the control of the first valve switch. The check valve is used to control the flow direction of the medicine. The medicine flows from the output end of the one-way valve to the input end of the mechanical diaphragm pump; Mechanical diaphragm pumps are used to pump medicines into the storage tank through the inlet port.

5. The dosing control method according to claim 4, characterized in that, The drug inlet pipeline is also equipped with a back pressure valve and a first filter; The input end of the back pressure valve is connected to both the drug inlet port and the output end of the mechanical diaphragm pump, and the output end of the back pressure valve is connected to both the output end of the check valve and the input end of the mechanical diaphragm pump. The first filter is located between the first valve switch and the check valve.

6. The dosing control method according to claim 3, characterized in that, The dispensing device includes multiple first dispensing branches, the input end of each first dispensing branch is connected to the dispensing port, and the output end of each first dispensing branch is connected to the corresponding flotation cell; Each of the first drug dispensing branches is sequentially equipped with a second valve switch, a first toothed flow meter, and a first electric needle valve; The first circular tooth flow meter is used to measure the flow rate of the reagent entering the first outlet branch, and the first electric needle valve controls the flow rate of the reagent entering the flotation cell.

7. The dosing control method according to claim 6, characterized in that, The drug dispensing device includes a main channel, a plurality of third valve switches arranged sequentially on the main channel, and a second drug dispensing branch with the same number of third valve switches; The main channel is connected to the drug outlet port; The input terminal of each second drug dispensing branch is connected to the output terminal of the corresponding third valve switch on the main road; Each third outlet branch is equipped with a second toothed flow meter and a second electric needle valve. The second toothed flow meter is used to measure the flow rate of the reagent entering the corresponding third outlet branch, and the second electric needle valve controls the flow rate of the reagent entering the flotation cell.

8. The dosing control method according to claim 7, characterized in that, A second filter is also installed on the main road; The second filter is installed between the drug outlet port and the first third valve switch.

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