A thickener control system

Abstract

This application discloses a thickener control system, including a thickener, a slurry injection unit, and a controller. The thickener has a slurry injection channel at the top and a slurry discharge outlet at the bottom. The slurry injection unit includes a flocculant delivery pump, a first buffer tank, and a first valve. The flocculant delivery pump is connected to the thickener, and the first valve is connected between the slurry injection channel and the first buffer tank. By connecting the first buffer tank to the slurry injection channel of the thickener and controlling the opening and closing of the first valve according to the slurry injection flow rate, density, and the operating frequency of the flocculant delivery pump, part of the injected slurry is diverted and temporarily stored in the first buffer tank. This allows the thickener to still operate efficiently and stably even when the maximum operating frequency of the flocculant delivery pump cannot meet the balance requirements of the slurry flow rate and density.

Description

Technical Field

[0001] This application relates to the field of thickening technology for laterite nickel ore slurry, specifically to a thickener control system. Background Technology

[0002] In the hydrometallurgical process of laterite nickel ore, a thickener is an important piece of equipment. It primarily uses gravity settling to gradually settle solid particles suspended in a liquid to the bottom of the container, increasing the solids concentration in the slurry or other suspensions. To ensure the thickener operates stably under changing conditions, Chinese patent CN209612286U provides a thickener control system. This control system includes a thickener, a flocculant delivery pump connected to the thickener, a first controller, an underflow pump, and a second controller. The stable operation of the thickener is controlled by dynamically adjusting the operating frequencies of the flocculant delivery pump and the underflow pump.

[0003] The existing technology has the following problems: the operating frequency of both the flocculant delivery pump and the underflow pump has extreme values. When the maximum adjustable frequency of the flocculant delivery pump and the underflow pump cannot meet the requirements of the working condition balance, the thickener still has unstable thickening effect. Summary of the Invention

[0004] The purpose of this application is to overcome the above-mentioned technical deficiencies and propose a thickener control system to solve the technical problem that, in the prior art, the thickener still has unstable thickening effect when the maximum adjustable frequency of the flocculant delivery pump and the underflow pump cannot meet the working condition balance requirements.

[0005] To achieve the above-mentioned technical objectives, this application adopts the following technical solution:

[0006] This application provides a thickener control system, including:

[0007] The thickener has a slurry injection channel at the top and a slurry discharge outlet at the bottom.

[0008] A slurry injection unit includes a flocculant delivery pump, a first buffer tank, and a first valve. The flocculant delivery pump is connected to the thickener, and the first valve is connected between the slurry injection channel and the first buffer tank.

[0009] The controller is electrically connected to both the flocculant delivery pump and the first valve. The controller is used to select whether to open or close the first valve based on the slurry flow rate and density of the thickener and the real-time operating frequency of the flocculant delivery pump.

[0010] In some embodiments, the system further includes a slurry discharge section, which includes a pumping component and a slow-containment component. Both the pumping component and the slow-containment component are connected and communicate with the slurry discharge outlet. The pumping component is used to pump out the slurry, and the slow-containment component is used to contain the slurry.

[0011] In some embodiments, the slow-release assembly includes a second buffer tank, a pump, and a second valve. One end of the second valve is connected to the slurry outlet, and the other end is connected to the pump. The other end of the pump is connected to the second buffer tank.

[0012] In some embodiments, the pumping assembly includes an underflow pump and a third valve, the underflow pump being connected to the slurry outlet via the third valve.

[0013] In some embodiments, the third valve is a three-way valve, with its three ends connected to the second buffer tank, the underflow pump, and the slurry outlet, respectively, for switching the connection status between the underflow pump and the second buffer tank, and between the underflow pump and the slurry outlet.

[0014] In some embodiments, the underflow pump, the pump, and the second valve are all electrically connected to the controller, which is used to select whether to open or close the second valve and the pump based on the bottom pressure value of the thickener and the real-time operating frequency of the underflow pump.

[0015] In some embodiments, the bottom of the first buffer tank is provided with a fourth valve connected to the slurry injection channel.

[0016] In some embodiments, both the first buffer tank and the second buffer tank are equipped with liquid level sensors.

[0017] In some embodiments, the discharge end of the underflow pump is connected to a slurry discharge channel, and both the slurry injection channel and the slurry discharge channel are equipped with flow meters and density meters, and the thickener is equipped with a pressure transmitter.

[0018] In some embodiments, the flocculant delivery pump is connected to a flocculant storage tank via a pipeline.

[0019] Compared with the prior art, the thickener control system provided in this application connects a first buffer tank to the slurry injection channel of the thickener, and controls the opening and closing of the first valve according to the slurry injection flow rate and density, as well as the working frequency of the flocculant delivery pump, to divert part of the injected slurry and temporarily store it in the first buffer tank. Thus, even when the maximum working frequency of the flocculant delivery pump cannot make the flocculant injection amount meet the balance requirements of slurry flow rate and density, the thickener can still operate efficiently and stably. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of the thickener control system provided in the embodiments of this application;

[0021] Figure 2 This is a control block diagram of the thickener control system provided in the embodiments of this application.

[0022] Explanation of reference numerals in the attached figures:

[0023] 1. Thickener; 101. Slurry Injection Channel; 102. Slurry Discharge Outlet; 103. Slurry Discharge Channel; 2. Slurry Injection Section; 21. Flocculant Delivery Pump; 22. First Buffer Tank; 23. First Valve; 24. Fourth Valve; 25. Flocculant Storage Tank; 3. Slurry Discharge Section; 31. Pumping Assembly; 311. Underflow Pump; 312. Third Valve; 32. Slow-release Assembly; 321. Second Buffer Tank; 322. Pumping Pump; 323. Second Valve; 4. Controller; 401. Level Sensor; 402. Flow Meter; 403. Densitometer; 404. Pressure Transmitter. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0025] To address the technical problem that the thickener still exhibits unstable thickening effects when the maximum adjustable frequencies of the flocculant delivery pump and the underflow pump cannot meet the operational balance requirements, this application provides a thickener control system that can maintain stable operation of the thickener even when the maximum adjustable frequencies of the flocculant delivery pump and the underflow pump cannot meet the operational balance requirements.

[0026] It should be noted that the thickener control system described in this application is used for, but not limited to, thickening of laterite nickel ore slurry. For ease of explanation, this application only uses the application of the thickener control system to thickening of laterite nickel ore slurry as an example. The principle of the thickener control system applied to other types of equipment is essentially the same as that applied to thickening of other slurries, and will not be elaborated here.

[0027] Please see Figure 1 and Figure 2 , Figure 1This is a schematic diagram of the thickener control system in one embodiment of this application. The thickener control system includes a thickener 1, a slurry injection unit 2, and a controller 4. The thickener 1 has a slurry injection channel 101 at its top and a slurry discharge outlet 102 at its bottom. The slurry injection unit 2 includes a flocculant delivery pump 21, a first buffer tank 22, and a first valve 23. The flocculant delivery pump 21 is connected to the thickener 1, and the other end of the flocculant delivery pump 21 is connected to a flocculant storage tank 25 via a pipeline for flocculant delivery. The first valve 23 is connected between the slurry injection channel 101 and the first buffer tank 22. When the first valve 23 is open, the slurry in the slurry injection channel 101 can be diverted to the first buffer tank 22. The flocculant delivery pump 21 and the first valve 23 are both electrically connected to the controller 4. The controller 4 is used to select whether to open or close the first valve 23 based on the slurry flow rate and density of the thickener 1 and the real-time operating frequency of the flocculant delivery pump 21. The flocculant delivery pump 21 is equipped with a frequency converter to adjust its operating frequency. When the slurry flow rate and density in the slurry injection channel 101 fluctuate, the controller 4 controls the operating frequency of the flocculant delivery pump 21 to adjust accordingly. When the slurry flow rate and density exceed the slurry flow rate and density values ​​that can be balanced by its maximum operating frequency, the first valve 23 is opened to divert the slurry, thereby balancing the slurry flow rate and density values ​​in the slurry injection channel 101 and matching the operating frequency of the flocculant delivery pump 21.

[0028] Understandably, in the control of the controller 4, a corresponding threshold is set for the flow rate and density value of the slurry injection channel 101. This threshold corresponds to the flocculant delivery flow rate corresponding to the maximum working frequency of the flocculant delivery pump 21. If the delivery flow rate cannot reach the balance with the slurry ratio, the first valve 23 is opened to divert the flow, thereby achieving a stable working state of the thickener 1.

[0029] Understandably, controller 4 can be a programmable logic controller (PLC). The PLC collects some operating parameters of the thickener and flocculant delivery pump (such as the slurry flow rate and density of the thickener, and the operating frequency of the flocculant delivery pump) to generate corresponding electrical signals, and transmits the electrical signals to the digital input card of the PLC. After passing through the digital input card, the corresponding digital signal is output to the first valve to control the opening or closing of the first valve.

[0030] In one embodiment, please refer to Figure 1In order to balance the pressure value of the thickened slurry accumulated at the bottom of the thickener 1 and the slurry discharge in the slurry discharge section 3, this application also includes a slurry discharge section 3. The slurry discharge section 3 includes a pumping component 31 and a slow-containment component 32. Both the pumping component 31 and the slow-containment component 32 are connected and communicate with the slurry discharge outlet 102. The pumping component 31 is used to pump out the slurry, and the slow-containment component 32 is used to contain the slurry. The pumping component 31 is used to perform the normal slurry discharge operation. When the pressure value caused by the accumulation of thickened slurry inside the thickener 1 is too high and exceeds the maximum frequency that the pumping component 31 can handle, the slow-containment component 32 is activated to divert and contain part of the slurry, so as to balance the amount of thickened slurry inside the thickener 1 and the amount of slurry pumped out.

[0031] Furthermore, the pumping assembly 31 includes an underflow pump 311 and a third valve 312. The underflow pump 311 is connected to the slurry outlet 102 through the third valve 312. By opening the third valve 312 and starting the underflow pump 311, the slurry at the bottom of the thickener 1 can be pumped out.

[0032] Furthermore, the slow-release assembly 32 includes a second buffer tank 321, a pump 322, and a second valve 323. One end of the second valve 323 is connected to the slurry outlet 102, and the other end is connected to the pump 322. The other end of the pump 322 is connected to the second buffer tank 321. By opening the second valve 323, the slurry at the bottom can be diverted and temporarily stored in the second buffer tank 321.

[0033] In one embodiment, please refer to Figure 1 In order to pump the slurry from the second buffer tank 321 within a controllable range, the third valve 312 is a three-way valve. The three ends of the three-way valve are respectively connected to the second buffer tank 321, the underflow pump 311, and the slurry outlet 102. It is used to switch the connection between the underflow pump 311 and the second buffer tank 321, or between the underflow pump 311 and the slurry outlet 102. When the underflow pump 311 is connected to the slurry outlet 102, the underflow pump 311 performs normal slurry pumping and discharge. When the underflow pump 311 is connected to the second buffer tank 321, the underflow pump 311 is used to pump and discharge the slurry temporarily stored in the second buffer tank 321.

[0034] Understandably, when the slurry pressure is within a controllable range, the slurry pumping out of the thickener 1 can be temporarily suspended, and the slurry in the second buffer tank 321 can be pumped out first to empty it. In addition, the pump 322 can also be a pump body that can pump in both directions, and a connecting pipe is set on the pipe at its inlet end to the discharge channel, and a valve is set up to pump out the slurry by reverse pumping.

[0035] In one embodiment, please refer to Figure 1 In order to discharge the slurry in the first buffer tank 22, a fourth valve 24 connected to the slurry injection channel 101 is provided at the bottom of the first buffer tank 22. When the slurry injection is within the controllable frequency range of the flocculant delivery pump 21, the fourth valve 24 can be opened to re-inject the slurry in the first buffer tank 22 into the thickener 1.

[0036] In one embodiment, please refer to Figure 1 The first buffer tank 22 and the second buffer tank 321 are both equipped with level sensors 401. The discharge end of the underflow pump 311 is connected to the slurry discharge channel 103. The slurry injection channel 101 and the slurry discharge channel 103 are both equipped with flow meters 402 and densitometers 403. The thickener 1 is equipped with a pressure transmitter 404. The flow meter 402 detects and collects the flow rate of the slurry, the densitometer 403 detects and collects the density of the slurry, and the pressure transmitter 404 detects and collects the pressure at the bottom of the thickener 1.

[0037] In this embodiment, please refer to Figure 2 The underflow pump 311, the pump 322, and the second valve 323 are all electrically connected to the controller 4. The controller 4 is used to select whether to open or close the second valve 323 and the pump 322 based on the bottom pressure value of the thickener 1 and the real-time operating frequency of the underflow pump 311. The level sensor 401, the flow meter 402, and the density meter 403 are also electrically connected to the controller 4. The controller 4 is a programmable logic controller. It controls the operating frequency of the flocculant delivery pump 21 based on the slurry condition of the slurry injection channel 101 detected by the flow meter 402 and the density meter 403; controls the operating frequency of the underflow pump 311 based on the pressure value of the pressure transmitter 404; controls whether to open the first valve 23 based on the operating frequency of the flocculant delivery pump 21; and controls whether to open the second valve 323 and the pump 322 based on the pressure value of the pressure transmitter 404.

[0038] To better understand this application, the following is combined with... Figures 1 to 2The technical solution of this application is described in detail as follows: The first valve, the second valve, and the fourth valve are all normally closed, while the third valve is initially open, connecting the thickener 1 and the underflow pump 311. When the slurry is injected, if it exceeds the controllable range of the flocculant delivery pump 21, i.e., exceeds the corresponding set thresholds for the slurry flow rate and density injected into the thickener and the maximum operating frequency of the flocculant delivery pump 21, then the first valve 23 is opened to divert the slurry and store it in the first buffer tank 22; when the slurry is discharged, if it exceeds the controllable range of the underflow pump 311, i.e., exceeds the corresponding set threshold for the bottom pressure value of the thickener 1 and the maximum operating frequency of the underflow pump 311, then the second valve 323 and the pump 322 are opened to divert and pump out the slurry and store it in the second buffer tank 321; when the flocculant delivery pump 21 is... Within a relatively loose and controllable range, when the first buffer tank 22 still contains slurry as detected by the level sensor 401, the fourth valve 24 is opened, and the slurry is discharged along with the injected slurry and injected into the thickener 1. When the slurry is discharged, the fourth valve is closed again. When the underflow pump 311 is within a relatively loose and controllable range, and the second buffer tank 321 still contains slurry as detected by the level sensor 401, the passage of the third valve 312 is switched to connect to the second buffer tank 321 to pump out the slurry inside. After the pumping is completed, the passage is switched back to the original passage.

[0039] The specific embodiments described above do not constitute a limitation on the scope of protection of this application. Any other corresponding changes and modifications made based on the technical concept of this application should be included within the scope of protection of the claims of this application.

Claims

1. A thickener control system, characterized in that, include: The thickener has a slurry injection channel at the top and a slurry discharge outlet at the bottom. A slurry injection unit includes a flocculant delivery pump, a first buffer tank, and a first valve. The flocculant delivery pump is connected to the thickener, and the first valve is connected between the slurry injection channel and the first buffer tank. The controller is electrically connected to both the flocculant delivery pump and the first valve. The controller is used to select whether to open or close the first valve based on the slurry flow rate and density of the thickener and the real-time operating frequency of the flocculant delivery pump.

2. The thickener control system according to claim 1, characterized in that, It also includes a slurry discharge section, which includes a pumping component and a slow-containment component. Both the pumping component and the slow-containment component are connected and communicate with the slurry discharge outlet. The pumping component is used to pump out the slurry, and the slow-containment component is used to contain the slurry.

3. The thickener control system according to claim 2, characterized in that, The slow-release assembly includes a second buffer tank, a pump, and a second valve. One end of the second valve is connected to the slurry outlet, and the other end is connected to the pump. The other end of the pump is connected to the second buffer tank.

4. The thickener control system according to claim 3, characterized in that, The pumping assembly includes an underflow pump and a third valve, wherein the underflow pump is connected to the slurry outlet via the third valve.

5. The thickener control system according to claim 4, characterized in that, The third valve is a three-way valve, with its three ends connected to the second buffer tank, the underflow pump, and the slurry outlet, respectively, to switch the connection status between the underflow pump and the second buffer tank, and between the underflow pump and the slurry outlet.

6. The thickener control system according to claim 5, characterized in that, The underflow pump, the pump, and the second valve are all electrically connected to the controller, which is used to select whether to open or close the second valve and the pump based on the bottom pressure value of the thickener and the real-time operating frequency of the underflow pump.

7. The thickener control system according to claim 6, characterized in that, The bottom of the first buffer tank is equipped with a fourth valve that is connected to the slurry injection channel.

8. The thickener control system according to claim 7, characterized in that, Both the first and second buffer tanks are equipped with liquid level sensors.

9. The thickener control system according to claim 8, characterized in that, The discharge end of the underflow pump is connected to a slurry discharge channel. Both the slurry injection channel and the slurry discharge channel are equipped with flow meters and density meters. The thickener is equipped with a pressure transmitter.

10. The thickener control system according to claim 9, characterized in that, The flocculant delivery pump is connected to a flocculant storage tank via a pipeline.

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