Chemical adding control method for coal slime flotation

Abstract

The invention relates to a dosing control method for coal slime flotation, belongs to the technical field of coal separation and processing, and solves the problem of poor control precision of a coal slime flotation dosing flow control method in the prior art. The dosing control method comprises the following steps: S1, determining an initial medicament flow rate pumped into a medicament storage box, so that the height of a medicament in the medicament storage box reaches a target height; s2, the initial needle valve opening degree corresponding to each flotation cell is determined, chemical adding is started, and the actual chemical flow of each flotation cell in the chemical adding process is obtained; s3, the needle valve opening degree of each flotation cell is adjusted, so that the actual reagent flow and the preset reagent flow of each flotation cell meet the flow error threshold value; s4, the actual height of the medicament in the medicament storage box in the dosing process is obtained, and the flow of the medicament pumped into the medicament storage box is adjusted by combining the target height, so that the height of the medicament in the medicament storage box is stabilized at the target height. Accurate control over the dosing flow of a plurality of flotation cells in the dosing process is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of coal sorting and processing, and in particular to a dosing control method for coal slime flotation. Background Art

[0002] Coal slime flotation is an important part of coal preparation production. The method and accuracy of flotation dosing are important factors affecting the flotation effect.

[0003] Coal slime flotation requires dosing at a tiny flow rate. The commonly used dosing control methods at home and abroad usually result in low control accuracy for tiny flows. At the same time, during the dosing process, the feed pressure is unstable, resulting in the inability of the reagent to be fully mixed with the slurry in the flotation tank. The added reagent is easily carried out with the overflowing foam, resulting in poor slurry mineralization effect and low impurity removal efficiency. This makes the control effect of coal preparation plants that have achieved automated flotation control dosing unsatisfactory.

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

[0005] In view of the above analysis, the embodiment of the present invention aims to provide a dosing control method for coal slime flotation, so as to solve the problem of poor control accuracy of the dosing flow control method for coal slime flotation in the prior art.

[0006] The embodiment of the present invention provides a dosing control method for coal slime flotation, the dosing control method comprising:

[0007] Step S1: determining the initial reagent flow rate pumped into the medicine storage box according to the preset reagent flow rates of the multiple flotation cells, so that the height of the reagent in the medicine storage box reaches the target height;

[0008] Step S2: determining the initial needle valve opening corresponding to each flotation cell according to the preset reagent flow rates of the multiple flotation cells and the corresponding flow interaction model, starting to add reagents, and obtaining the actual reagent flow rate of each flotation cell during the dosing process;

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

[0010] Step S4: obtaining the actual height of the medicine in the medicine storage box during the dosing process, and adjusting the flow rate of the medicine pumped into the medicine storage box in combination with the target height, so that the height of the medicine in the medicine storage box is stabilized at the target height.

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

[0012]

[0013] Among them, μ n (t) represents the needle valve opening of the nth flotation cell after adjustment, L n represents the preset reagent flow rate of the nth flotation cell, N represents the number of flotation cells, K Lp Indicates the flow rate proportional gain coefficient, L no (t) represents the actual reagent flow rate of the nth flotation cell, K Li represents the flow integral gain coefficient, t represents any time, τ represents the integral variable, and the value ranges 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 drug pumped into the drug storage box is adjusted according to the following formula:

[0015]

[0016] Among them, L'(t) represents the flow rate of the medicine pumped into the medicine storage tank after adjustment, K Hp represents the height proportional gain coefficient, H represents the target height, H(t) represents the actual height of the medicine in the medicine storage box, K Hi Represents the height integral gain coefficient.

[0017] Based on the further improvement of the above 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 reagent flow rate data is fitted to obtain the relationship between the reagent flow rate of all flotation cells and the needle valve opening of all flotation cells as a flow interaction model.

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

[0021] The medicine discharging device allows the medicine to flow to a plurality of flotation tanks through the medicine discharging port. Two ports are opened at the bottom of the medicine storage box, which are respectively used as a medicine inlet port and a medicine discharging port.

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

[0023] One end of the drug feeding pipeline is connected to the drug feeding port, and the other end serves as a drug feeding end;

[0024] The medicine flows to the input end of the one-way valve under the control of the first valve switch, and the one-way valve is used to control the flow direction of the medicine;

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

[0026] A mechanical diaphragm pump is used to pump the medicine into the medicine storage tank through the medicine inlet port.

[0027] Based on the further improvement of the above-mentioned dosing control method, a back pressure valve and a first filter are further provided on the drug inlet pipeline;

[0028] The input end of the back pressure valve is connected to the drug inlet port and the output end of the mechanical diaphragm pump at the same time, and the output end of the back pressure valve is connected to the output end of the one-way valve and the input end of the mechanical diaphragm pump;

[0029] The first filter is disposed between the first valve switch and the one-way valve.

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

[0031] Each first medicine outlet branch is provided with a second valve switch, a first spherical tooth flow meter and a first electric needle valve in sequence;

[0032] The first spherical tooth flowmeter is used to measure the flow rate of the reagent entering the first reagent outlet branch, and the first electric needle valve controls the flow rate of the reagent entering the flotation tank.

[0033] Based on the further improvement of the above-mentioned dosing control method, the drug discharging device includes a main road, a plurality of third valve switches sequentially arranged on the main road, and a second drug discharging branch road having the same number as the third valve switches;

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

[0035] The input end of each second medicine outlet branch is connected to a position on the main road corresponding to the output end of the third valve switch;

[0036] A second spherical tooth flowmeter and a second electric needle valve are sequentially arranged on each third medicine outlet branch. The second spherical tooth flowmeter is used to measure the flow of the medicine entering the corresponding third medicine outlet branch, and the second electric needle valve controls the flow of the medicine entering the flotation tank.

[0037] Based on the further improvement of the above-mentioned dosing control method, a second filter is also provided on the main road;

[0038] The second filter is arranged between the medicine 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, so 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, during the dosing process, the reagent height in the reagent storage box is kept stable, so that the reagent added to the flotation cell can be fully mixed with the slurry, and the mineralization effect is good;

[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 in front of the flow 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 meet the preset reagent flow rate at the same time;

[0042] 3. By determining the initial needle valve opening corresponding to each flotation cell at the beginning of the dosing process as a feedforward control, combined with adjusting the needle valve opening of the corresponding flotation cell according to the actual reagent flow rate and the preset reagent flow rate of the flotation cell 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, further improving the dosing accuracy.

[0043] In the present invention, the above-mentioned technical solutions can also be combined with each other to achieve more preferred combination solutions. Other features and advantages of the present invention will be described in the subsequent description, and some advantages can become obvious from the description, or can be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained through the contents particularly pointed out in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The drawings are only for the purpose of illustrating particular embodiments and are not to be considered limiting of the present invention. Like reference symbols denote like components throughout the drawings.

[0045] Figure 1 A schematic flow chart of a dosing control method for coal slime flotation provided by an embodiment of the present invention;

[0046] Figure 2 A schematic structural diagram of a method for controlling the dosing of coal slime flotation provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0047] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a 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 used to limit the scope of the present invention.

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

[0049] Step S1: determining the initial reagent flow rate pumped into the medicine storage box according to the preset reagent flow rates of the multiple flotation cells, so that the height of the reagent in the medicine storage box reaches the target height;

[0050] Step S2: determining the initial needle valve opening corresponding to each flotation cell according to the preset reagent flow rates of the multiple flotation cells and the corresponding flow interaction model, starting to add reagents, and obtaining the actual reagent flow rate of each flotation cell during the dosing process;

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

[0052] Step S4: obtaining the actual height of the medicine in the medicine storage box during the dosing process, and adjusting the flow rate of the medicine pumped into the medicine storage box in combination with the target height, so that the height of the medicine in the medicine storage box is stabilized at the target height.

[0053] Specifically, the process of coal slime flotation includes two major stages: before the dosing process and during the dosing process. Figure 1 As shown, step S1 is the preparation work before the dosing process begins. After the initial needle valve opening of each flotation cell is determined in step S2, the dosing process can be started. During the dosing process, the actual reagent flow rate corresponding to 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 maintained to meet the flow error threshold of the preset reagent flow rate, so as to achieve accurate dosing of each flotation cell, stabilize the height of the reagent in the reagent storage box at the target height, stabilize the dosing pressure, and enable the reagent to fully mix and react with the slurry after entering the flotation cell.

[0054] Specifically, Figure 1As shown, in step S1, the preset flow rate reagent in each flotation cell can be reasonably set according to the actual situation, and can be the same or different; the dosing process is not limited to a single flotation cell, and multiple flotation cells can be dosed at the same time, which has a wide range of applications and can be used for dosing of coal slime flotation in various scenarios. The drug storage box serves as a transfer station for storing reagents and also provides a power source for dosing. Before the dosing process begins, the reagent needs to be pumped into the drug storage box, and the target height of the reagent in the drug storage box is determined in advance.

[0055] Specifically, in step S1, after determining the preset reagent flow rates of multiple flotation cells, it can be known that the reagent flow rate that needs to be continuously pumped into the medicine storage box during the dosing process, and the sum of the preset reagent flow rates of multiple flotation cells is used as the initial reagent flow rate pumped into the medicine storage box. This can avoid large changes in the reagent flow rate pumped into the medicine storage box as much as possible during the formal dosing process, and the adjustment is more smooth and natural; at the same time, the reagent flow rate pumped into the medicine storage box is also used as a feedforward control to maintain the height of the reagent in the medicine storage box.

[0056] Specifically, Figure 1 As shown, in step S2, after the reagent height in the medicine storage box reaches the target height, the initial needle valve opening corresponding to each flotation cell is adjusted. It can be understood that the needle valve opening of each flotation cell corresponds to the flow rate of the reagent added to each flotation cell. The initial needle valve opening of each flotation cell is determined according to the preset reagent flow rate of each flotation cell and the flow interaction model constructed in advance, that is, the approximate range of the reagent flow rate added to each flotation cell is determined. There is still a certain error between this range and the preset reagent flow rate, but the difference is small, which serves as feedforward control.

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

[0058] Specifically, both step S3 and step S4 are stages of the dosing process, during which the error between the actual reagent flow rate of each flotation cell and the preset reagent flow rate must always satisfy the flow error threshold. The flow error threshold can be reasonably set in advance according to the specific situation, so that the dosing control method can be reasonably set according to different slurries and has a wide range of applications.

[0059] Specifically, in step S3, by adjusting the needle valve opening of each flotation cell, the actual reagent flow rate entering each flotation cell changes, thereby making the actual reagent flow rate as close to the preset reagent flow rate as possible. It is worth noting that 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 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] Among them, μ n (t) represents the needle valve opening of the nth flotation cell after adjustment, L n represents the preset reagent flow rate of the nth flotation cell, N represents the number of flotation cells, K Lp Indicates the flow rate proportional gain coefficient, L no (t) represents the actual reagent flow rate of the nth flotation cell, K Li represents the flow integral gain coefficient, t represents any time, τ represents the integral variable, and the value ranges from 0 to t.

[0063] Specifically, the needle valve opening required for each adjustment can be determined by the above formula for adjusting the needle valve opening of each flotation cell. It is understandable that when determining the needle valve opening required for the next adjustment, it is necessary to calculate it based on the actual reagent flow rate after the last adjustment and the preset reagent flow rate.

[0064] It is worth noting that the flow proportional gain coefficient corresponding to each flotation cell is set to be the same, and at the same time, a proportional coefficient is further added in front of the flow proportional gain coefficient according to the preset reagent flow 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 obtained by each flotation cell can meet the preset reagent flow at the same time.

[0065] Specifically, Figure 1 As shown, in step S4, the actual height of the medicine in the medicine storage box during the dosing process is obtained, and the flow rate of the medicine pumped into the medicine storage box is adjusted in combination with the target height, so that the height of the medicine in the medicine storage box is stabilized at the target height. It can be understood that during the dosing process, since the flow rate of the medicine pumped into the medicine storage box and the flow rate of the medicine flowing out of the medicine storage box change, the height of the medicine in the medicine storage box also changes. In order to stabilize the pressure of the medicine flowing out of the medicine storage box, the height of the medicine in the medicine storage box must be stabilized at the target height.

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

[0067]

[0068] Among them, L'(t) represents the flow rate of the medicine pumped into the medicine storage tank after adjustment, K Hp represents the height proportional gain coefficient, H represents the target height, H(t) represents the actual height of the medicine in the medicine storage box, K HiRepresents the height integral gain coefficient.

[0069] Specifically, the target altitude, altitude proportional gain coefficient and altitude integral gain coefficient are all parameters set in advance.

[0070] Specifically, a suitable gain coefficient may be obtained by performing multiple tests.

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

[0072] Preferably, during the drug addition process, the drug is allowed to enter the drug storage box through the drug inlet port by the drug inlet device;

[0073] The medicine discharging device allows the medicine to flow to a plurality of flotation tanks through the medicine discharging port. Two ports are opened at the bottom of the medicine storage box, which are respectively used as a medicine inlet port and a medicine discharging port.

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

[0075] Specifically, Figure 2 As shown, the drug feeding device includes a drug feeding pipeline, and a first valve switch, a one-way valve and a mechanical diaphragm pump which are sequentially arranged in the drug feeding pipeline;

[0076] One end of the drug feeding pipeline is connected to the drug feeding port, and the other end serves as a drug feeding end;

[0077] The medicine flows to the input end of the one-way valve under the control of the first valve switch, and the one-way valve is used to control the flow direction of the medicine;

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

[0079] A mechanical diaphragm pump is used to pump the medicine into the medicine storage tank through the medicine inlet port.

[0080] Preferably, the drug inlet pipeline is also provided with a back pressure valve and a first filter;

[0081] The input end of the back pressure valve is connected to the drug inlet port and the output end of the mechanical diaphragm pump at the same time, and the output end of the back pressure valve is connected to the output end of the one-way valve and the input end of the mechanical diaphragm pump;

[0082] The first filter is disposed between the first valve switch and the one-way valve.

[0083] Specifically, Figure 2As shown, the medicine enters the medicine feeding device from the medicine feeding end, and passes through the first valve switch, the first filter, the one-way valve and the mechanical diaphragm pump arranged on the medicine feeding pipeline in sequence. The mechanical diaphragm pump is used to pump the medicine into the medicine storage box through the medicine feeding port 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 to play a role in pre-removal of impurities. Preferably, the first filter is a Y-type filter.

[0085] Specifically, under the control of the one-way valve, the medicine can only enter the mechanical diaphragm pump from the upward direction. As the mechanical diaphragm pump works, the medicine enters the medicine inlet port, effectively preventing the medicine from flowing back.

[0086] Specifically, by adjusting the motor speed of the mechanical diaphragm pump, the flow rate of the medicine in the medicine inlet pipeline can be adjusted, and then the flow rate of the medicine pumped into the medicine storage box can be controlled.

[0087] Specifically, when the medicine dispensing device in the medicine storage box is blocked, the pressure of the medicine inlet pipeline below will be too high. In order to avoid damaging the medicine inlet pipeline, a back pressure valve can be set to effectively reduce the pressure of the medicine inlet pipeline below. It is worth noting that the back pressure valve can only flow in one direction, that is, it can only flow from top to bottom, and cannot flow in the opposite direction.

[0088] In one embodiment, the drug discharging device comprises a plurality of first drug discharging branches, the input end of each first drug discharging branch is connected to the drug discharging port, and the output end of each first drug discharging branch is connected to the corresponding flotation tank;

[0089] Each first medicine outlet branch is provided with a second valve switch, a first spherical tooth flow meter and a first electric needle valve in sequence;

[0090] The first spherical tooth flowmeter is used to measure the flow rate of the reagent entering the first reagent outlet branch, and the first electric needle valve controls the flow rate of the reagent entering the flotation tank.

[0091] Specifically, the input end of each first drug outlet branch is connected to the drug outlet port, so that the drug flow rate out of the drug outlet port can flow evenly to different flotation cells, and multiple flotation cells with the same preset drug flow rate can be quickly and conveniently added with drugs, so that the drugs are fully mixed with the slurry in the flotation cell.

[0092] Specifically, the second valve switch, the first spherical tooth flowmeter and the first electric needle valve sequentially arranged on the first medicine outlet branch can effectively control, measure the flow rate and adjust the medicine flow rate of the medicine entering the first medicine outlet branch.

[0093] In another embodiment, the medicine discharging device includes a main road, a plurality of third valve switches sequentially arranged on the main road, and a second medicine discharging branch road having the same number as the third valve switches;

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

[0095] The input end of each second medicine outlet branch is connected to a position on the main road corresponding to the output end of the third valve switch;

[0096] A second spherical tooth flowmeter and a second electric needle valve are sequentially arranged on each third medicine outlet branch. The second spherical tooth flowmeter is used to measure the flow of the medicine entering the corresponding third medicine outlet branch, and the second electric needle valve controls the flow of the medicine entering the flotation tank.

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

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

[0099] Specifically, Figure 2 As shown, a plurality of third valve switches and second medicine outlet branches having the same number as the third valve switches are sequentially arranged on the main road of the medicine outlet device; the medicine outlet port is connected to the main road to direct the medicine in the medicine storage box to the main road, and the main road distributes the medicine to different second medicine outlet branches through the third valve switches, and on each second medicine outlet branch, the medicine passes through the second spherical tooth flowmeter and the second electric needle valve in sequence and enters the flotation tank.

[0100] Specifically, Figure 2 As shown, a second filter is also provided on the main road, and the second filter is used for post-impurity removal. The mesh number of the filter is higher than that of the first filter, and it can effectively prevent the medicine flowing out of the medicine outlet port from clogging the second electric needle valve and the second round tooth flow meter.

[0101] It is worth noting that if Figure 2 As shown, the medicine storage box is placed at a high position, and the medicine is continuously pumped into the medicine storage box through the medicine feeding device. When medicine addition is required, the medicine is flowed to each flotation tank for addition under the action of gravity through the medicine discharging device.

[0102] Preferably, each second electric needle valve is arranged at the same height, so as to improve the coordination of different electric needle valves and increase the stability of the drug flow regulation.

[0103] Specifically, a first filter and a second filter are respectively arranged in the medicine inlet device and the medicine outlet device, and impurities in the medicine are removed through double filtration.

[0104] Specifically, when the dosing process starts, the initial opening of the second electric needle valve is determined according to 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 spherical tooth flowmeter, and the opening of the second electric needle valve is adjusted according to the comparison result of the actual reagent flow rate and the preset reagent flow rate 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 dosing agent flow rate of the dosing mechanism. Figure 2 As shown, when the opening of all the second electric needle valves is opened to the maximum, the cross-sectional area through which the medicine flows is maximized. When the maximum medicine flow rate of the dosing mechanism is known, the speed at which the medicine flows can be calculated. The speed is proportional to the height of the medicine in the medicine storage box, that is, the higher the height of the medicine in the medicine storage box, the greater the speed. In this way, the height of the medicine that meets the maximum medicine flow rate can be determined, and this height can be used as the target height and set in advance.

[0107] Specifically, before the dosing process begins, the initial motor speed of the mechanical diaphragm pump is determined according to the preset reagent flow rate of each flotation tank, so that the height of the reagent in the medicine storage box 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 medicine storage box, so that the actual height of the medicine storage box is stabilized at the target height.

[0109] Specifically, a liquid level meter may be provided in the medicine storage box to measure the actual height of the medicine in the medicine storage box in real time.

[0110] Preferably, if Figure 2 As shown, a pressure gauge may also be provided at the medicine outlet port, and the actual height of the medicine in the medicine storage box may also be determined by the pressure gauge.

[0111] Specifically, Figure 2 As shown, before the dosing process begins, the reagent is pumped into the medicine storage box through the medicine feeding device so that the height of the reagent in the medicine storage box reaches the target height; when the dosing process begins, the reagent enters multiple flotation tanks through the medicine discharging device under the action of gravity.

[0112] Specifically, during the dosing process, the height of the medicine in the medicine storage box needs to be maintained stable at a target height, and at this time, the medicine needs to be continuously pumped into the medicine storage box through a medicine feeding device.

[0113] It is worth noting that the embodiment of the present invention utilizes the predictive ability of feedforward control and the regulating ability of feedback control, especially when the flow demand changes dynamically, to achieve coordinated control of the reagent flow, avoid interference and conflict, ensure the actual reagent flow of each flotation cell, meet the preset reagent flow of the corresponding flotation cell, and improve the dosing accuracy by stabilizing the reagent height in the medicine storage box at the target height.

[0114] Preferably, the traffic interaction model is determined by 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 reagent flow rate data is fitted to obtain the relationship between the reagent flow rate of all flotation cells and the needle valve opening of all flotation cells as a flow interaction model.

[0117] Specifically, the opening of each second electric needle valve is determined, from fully closed to fully open. For example, the opening of fully closed is 0, and the opening of fully open is 9. Then, from fully closed to fully open, each second electric needle valve includes 10 openings. If there are 3 flotation cells for simultaneous dosing, then for the 3 second electric needle valves, there are 1,000 opening combinations. If more flotation cells are used for simultaneous dosing, more opening combinations will be included.

[0118] It is worth noting that several opening combinations can be selected from all opening combinations for experiments to obtain the opening of the second electric needle valve and the reagent flow data of each flotation cell under the several opening combinations. The corresponding relationship between the opening of all second electric needle valves and the reagent flow of all flotation cells can be obtained by fitting the reagent flow data as a flow interaction model.

[0119] Specifically, in the flow interaction model, under each opening combination, there is a corresponding preset reagent flow rate of each flotation cell. After fitting, the preset reagent flow rates of all flotation cells may also have corresponding openings of the second electric needle valve.

[0120] Compared with the prior art, the embodiment of the present invention provides a dosing control method for coal slime flotation. 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, so that the reagent flow rate entering the multiple flotation cells meets the preset flow rate requirements of each flotation cell, and the accuracy of flow control is improved. At the same time, during the dosing process, the reagent height in the reagent storage box is maintained stable, so that the reagent added to the flotation cell can be fully mixed with the ore pulp, and the mineralization effect is good; moreover, 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 after the last adjustment, and the adjustment time is adjusted. In combination with the preset reagent flow of all flotation cells, a proportional coefficient is added before the flow proportional gain coefficient 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 obtained by each flotation cell can meet the preset reagent flow at the same time; at the same time, by determining the initial needle valve opening corresponding to each flotation cell at the beginning of the dosing process as a feedforward control, combined with adjusting the needle valve opening of the corresponding flotation cell according to the actual reagent flow and the preset reagent flow of the flotation cell during the dosing process as feedback control, the reagent flow added to each flotation cell can meet the preset flow requirement of each flotation cell as much as possible, thereby further improving the dosing accuracy.

[0121] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A dosing control method for coal slime flotation, characterized in that: The dosing control method comprises: Step S1: determining the initial reagent flow rate pumped into the medicine storage box according to the preset reagent flow rates of the multiple flotation cells, so that the height of the reagent in the medicine storage box reaches the target height; Step S2: determining the initial needle valve opening corresponding to each flotation cell according to the preset reagent flow rates of the multiple flotation cells and the corresponding flow interaction model, starting to add reagents, and obtaining the actual reagent flow rate of each flotation cell during the dosing process; Step S3: adjusting the needle valve opening of each flotation cell according to the actual reagent flow rate of each flotation cell during the dosing process and the preset reagent flow rate of the corresponding flotation cell, so that the actual reagent flow rate of each flotation cell and the preset reagent flow rate meet the flow error threshold; Step S4: obtaining the actual height of the medicine in the medicine storage box during the dosing process, and adjusting the flow rate of the medicine pumped into the medicine storage box in combination with the target height, so that the height of the medicine in the medicine storage box is stabilized at the target height.

2. The dosing control method according to claim 1, characterized in that: In step S3, the needle valve opening of each flotation cell is adjusted according to the following formula: Among them, μ n (t) represents the needle valve opening of the nth flotation cell after adjustment, L n represents the preset reagent flow rate of the nth flotation cell, N represents the number of flotation cells, K Lp Indicates the flow rate proportional gain coefficient, L no (t) represents the actual reagent flow rate of the nth flotation cell, K Li represents the flow integral gain coefficient, t represents any time, τ represents the integral variable, and the value ranges from 0 to t.

3. The dosing control method according to claim 2, characterized in that: In step S4, the flow rate of the medicine pumped into the medicine storage box is adjusted according to the following formula: Among them, L'(t) represents the flow rate of the medicine pumped into the medicine storage tank after adjustment, K Hp represents the height proportional gain coefficient, H represents the target height, H(t) represents the actual height of the medicine in the medicine storage box, K Hi Represents the height integral gain coefficient.

4. The dosing control method according to claim 1, characterized in that: Determine the traffic interaction model 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 reagent flow rate data is fitted to obtain the relationship between the reagent flow rate of all flotation cells and the needle valve opening of all flotation cells as a flow interaction model.

5. The dosing control method according to claim 1, characterized in that: During the dosing process, the medicine is fed into the medicine storage box through the medicine feeding port by the medicine feeding device; The medicine discharging device allows the medicine to flow to a plurality of flotation tanks through the medicine discharging port. Two ports are opened at the bottom of the medicine storage box, which are respectively used as a medicine inlet port and a medicine discharging port.

6. The drug addition control method according to claim 5, characterized in that: The drug feeding device comprises a drug feeding pipeline, and a first valve switch, a one-way valve and a mechanical diaphragm pump which are sequentially arranged in the drug feeding pipeline; One end of the drug feeding pipeline is connected to the drug feeding port, and the other end serves as a drug feeding end; The medicine flows to the input end of the one-way valve under the control of the first valve switch, and the one-way valve is used to control the flow direction of the medicine; The medicine flows through the output end of the one-way valve to the input end of the mechanical diaphragm pump; A mechanical diaphragm pump is used to pump the medicine into the medicine storage tank through the medicine inlet port.

7. The drug addition control method according to claim 6, characterized in that: The drug inlet pipeline is also provided with a back pressure valve and a first filter; The input end of the back pressure valve is connected to the drug inlet port and the output end of the mechanical diaphragm pump at the same time, and the output end of the back pressure valve is connected to the output end of the one-way valve and the input end of the mechanical diaphragm pump; The first filter is disposed between the first valve switch and the one-way valve.

8. The drug addition control method according to claim 5, characterized in that: The drug discharging device comprises a plurality of first drug discharging branches, the input end of each first drug discharging branch is connected to the drug discharging port, and the output end of each first drug discharging branch is connected to the corresponding flotation tank; Each first medicine outlet branch is provided with a second valve switch, a first spherical tooth flow meter and a first electric needle valve in sequence; The first spherical tooth flowmeter is used to measure the flow rate of the reagent entering the first reagent outlet branch, and the first electric needle valve controls the flow rate of the reagent entering the flotation tank.

9. The drug addition control method according to claim 8, characterized in that: The medicine discharging device comprises a main road, a plurality of third valve switches arranged in sequence on the main road, and a second medicine discharging branch road having the same number as the third valve switches; The main channel is connected to the medicine outlet port; The input end of each second medicine outlet branch is connected to the position on the main road corresponding to the output end of the third valve switch; A second spherical tooth flowmeter and a second electric needle valve are sequentially arranged on each third medicine outlet branch. The second spherical tooth flowmeter is used to measure the flow of the medicine entering the corresponding third medicine outlet branch, and the second electric needle valve controls the flow of the medicine entering the flotation tank.

10. The drug addition control method according to claim 9, characterized in that: A second filter is also provided on the main road; The second filter is arranged between the medicine outlet port and the first third valve switch.

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