Quantitative control method and control system for material conveying system
By setting the target value of the discharge volume and the filter rate in the centrifuge, and adjusting the opening degree of the feed regulating valve with the controller, the problem of uncertainty in the discharge volume caused by the change of the screen hole size is solved, and the precise control of the discharge volume and the improvement of production efficiency is achieved.
Patent Information
- Application Number
- CN202510490577.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-18
- Publication Date
- 2025-08-05
AI Technical Summary
During the discharge process of centrifuge, changes in the screen mesh pore size leads to an increase in uncertainty in the discharge volume, resulting in low production efficiency and increased costs. The existing technology cannot effectively solve the problem by regularly replacing the screen mesh.
By setting the target value of the discharge quantity and the target value of the filter rate, the controller is used to calculate the filter rate and discharge volume of the centrifuge, and adjust the opening degree of the feed regulating valve according to the difference, so as to achieve accurate control of the discharge volume of the centrifuge and prevent the change in the screen hole diameter from affecting the discharge volume.
It realizes controllability of the centrifuge discharge volume, improves production efficiency and screen usage cycle, and ensures product quality and production process accuracy.
Smart Images
Figure CN120420731A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a quantitative control method and a control system for a material conveying system. Background Art
[0002] In the transportation of solid materials, such as carnallite solid ore, a material conveying system is typically used to improve conveying efficiency. Specifically, the carnallite ore is first mixed with a solution to form a solid-liquid mixture, or slurry. During this process, the solid and liquid phases are immiscible, or, when equilibrium is reached, the components remain unchanged. The slurry is then pumped through the system. At the end of the transport, the slurry is separated into solid and liquid using a centrifuge, and the resulting solid phase is transferred to the next process.
[0003] Carnallite is produced by drying in salt lake brine rich in potassium, lithium, magnesium and other minerals. It is the main raw material for producing potassium chloride. In the process of producing potassium chloride, the material slurry is separated into solid and liquid by a centrifuge, and the solid potassium chloride material obtained is used as the raw material for potassium chloride production.
[0004] Quantitative discharging means that during the discharging process, the centrifuge outputs materials in a pre-set, fixed amount according to the process requirements to meet the requirements of process production.
[0005] However, when the centrifuge is operating, some solids smaller than the mesh size will enter the filtrate along with the liquid. These tiny solids will wear out the mesh during the filtration process. After a period of operation, the mesh size will increase, and the solids filtration rate will also increase, resulting in increasing uncertainty in the centrifuge output. Setting a set usage time for the mesh and regularly replacing it not only increases operating costs, but also interrupts the production line when the centrifuge is down, reducing production efficiency.
[0006] The purpose of the present invention is to solve the above problems of the prior art and provide a quantitative control method and a discharge control system for a material conveying system, so as to achieve quantitative discharge of the centrifuge and improve the service life of the screen. Summary of the Invention
[0007] In order to solve the above problems, the present invention provides a quantitative control method for a material conveying system, comprising: a target value setting step S1, setting a discharge target value m and a filtration rate target value t. A parameter acquisition step S3, acquiring a feed slurry concentration value, a feed slurry flow value, a filtrate concentration value, a filtrate flow value, and a feed slurry liquid phase concentration value. A calculation step S4, calculating a centrifuge filtration rate T and a centrifuge discharge volume M. A filtration rate comparison step S5, comparing the centrifuge filtration rate T with the filtration rate target value t. When the centrifuge filtration rate T is greater than or equal to the filtration rate target value, an over-limit filtration alarm is output to remind the centrifuge screen to be replaced.
[0008] When the centrifuge filtration rate T is less than the target filtration rate value t, the process proceeds to the discharge control step S6. In the discharge control step S6, the centrifuge discharge volume M is compared with the discharge volume target value m. When the centrifuge discharge volume M is greater than the discharge volume target value m, the opening of the feed regulating valve 14 is gradually reduced, and the process returns to the parameter acquisition step S3. When the centrifuge discharge volume M is equal to the discharge volume target value m, the opening of the feed regulating valve 14 is not adjusted, and the process returns to the parameter acquisition step S3. When the centrifuge discharge volume M is less than the discharge volume target value m, the opening of the feed regulating valve 14 is gradually increased, and the process returns to the parameter acquisition step S3.
[0009] Preferably, in the calculation step S4, Centrifuge discharge capacity M= 1×Q1 - 2×Q2 Centrifuge penetration rate
[0010] in, 1 is the feed slurry concentration value, Q1 is the feed slurry flow value, 2 is the filtrate concentration value, Q2 is the filtrate flow value, 3 is the feed slurry liquid phase concentration value.
[0011] Preferably, in the discharge control step S6, when the difference between the centrifuge discharge volume M and the discharge volume target value m is large, the opening of the feed regulating valve 14 is adjusted to a greater extent, and the adjustment time interval is shorter. When the difference between the centrifuge discharge volume M and the discharge volume target value m is small, the opening of the feed regulating valve 14 is adjusted to a lesser extent, and the adjustment time interval is longer.
[0012] Preferably, in the discharge control step S6, when 0%m≤M<50%m, the feed regulating valve 14 is opened at an amplitude of 5%-10% of the total stroke each time, and the interval between each execution is 3-5 seconds. When 50%m≤M<75%m, the feed regulating valve 14 is opened at an amplitude of 3%-5% of the total stroke each time, and the interval between each execution is 3-5 seconds. When 75%m≤M<90%m, the feed regulating valve 14 is opened at an amplitude of 1.5%-3% of the total stroke each time, and the interval between each execution is 3-5 seconds. When 90%m≤M<95%m, the feed regulating valve 14 is opened at an amplitude of 0.5%-1.5% of the total stroke each time, and the interval between each execution is 5-10 seconds.
[0013] When 95%m≤M<99%m, the feed regulating valve 14 is opened at a range of 0.1%-0.5% of the total stroke each time, with an interval of 10-20 seconds between each execution. When 99%m≤M<100%m, the feed regulating valve 14 is opened at a range of 0.05%-0.1% of the total stroke each time, with an interval of 30-60 seconds between each execution. When 100%m<M<101%m, the feed regulating valve 14 is opened at a range of 0.05%-0.1% of the total stroke each time, with an interval of 30-60 seconds between each execution. When 101%m≤M<105%m, the feed regulating valve 14 is closed at a range of 0.1%-0.5% of the total stroke each time, with an interval of 10-20 seconds between each execution.
[0014] When 105%m≤M<110%m, the feed regulating valve 14 is closed at a range of 0.5%-1.5% of the total stroke each time, with an interval of 5-10 seconds between each execution. When 110%m≤M<125%m, the feed regulating valve 14 is closed at a range of 1.5%-3% of the total stroke each time, with an interval of 3-5 seconds between each execution. When 125%m≤M<150%m, the feed regulating valve 14 is closed at a range of 3%-5% of the total stroke each time, with an interval of 3-5 seconds between each execution. When 150%m≤M, the feed regulating valve 14 is closed at a range of 5%-10% of the total stroke each time, with an interval of 3-5 seconds between each execution.
[0015] Preferably, in the discharge control step S6, when the centrifuge discharge volume M is less than the discharge volume target value m, it also includes judging whether the opening of the feed regulating valve 14 reaches the maximum value. When the opening of the feed regulating valve 14 reaches the maximum value, an alarm is issued; otherwise, the feed regulating valve 14 is gradually opened and the process returns to the parameter acquisition step S3.
[0016] The quantitative control system of the material conveying system includes a controller 3, which includes a filtration rate calculation module 31, a discharge amount calculation module 32, a judgment module 35, an alarm module 33 and a control module 34. The controller 3 obtains the feed slurry concentration value, the feed slurry flow value, the filtrate concentration value, the filtrate flow value and the feed slurry liquid phase concentration value.
[0017] The filtration rate calculation module 31 is used to calculate the centrifuge filtration rate T based on the feed slurry concentration value, feed slurry flow value, filtrate concentration value, filtrate flow value, and feed slurry liquid phase concentration value. The discharge amount calculation module 32 is used to calculate the centrifuge discharge amount M based on the feed slurry concentration value, feed slurry flow value, filtrate concentration value, and filtrate flow value. The judgment module 35 is used to compare the centrifuge filtration rate T with the filtration rate target value t, and compare the centrifuge discharge amount M with the discharge amount target value m.
[0018] The control module 34 is configured to close the feed regulating valve 14 when a centrifuge malfunction occurs. When the centrifuge discharge volume M exceeds the target discharge volume m, the opening of the feed regulating valve 14 is gradually reduced. When the centrifuge discharge volume M is less than the target discharge volume m, the opening of the feed regulating valve 14 is gradually increased. When the centrifuge discharge volume M equals the target discharge volume m, the opening of the feed regulating valve 14 is not adjusted. The alarm module 33 is configured to issue a fault alarm when a centrifuge malfunction occurs. When the centrifuge filtration rate T is greater than or equal to the target filtration rate t, an over-limit filtration alarm is output, prompting the user to replace the centrifuge screen.
[0019] Preferably, the filtration rate calculation module 31 is used to calculate the centrifuge filtration rate according to the following formula: , Centrifuge discharge capacity M= 1×Q1 - 2×Q2 The discharge amount calculation module 32 is used to calculate the centrifuge discharge amount M according to the following formula: Centrifuge penetration rate ; in, 1 is the feed slurry concentration value, Q1 is the feed slurry flow value, 2 is the filtrate concentration value, Q2 is the filtrate flow value, 3 is the feed slurry liquid phase concentration value.
[0020] Preferably, the control module 34 is used to make large adjustments to the feed regulating valve 14 with a short adjustment time interval when the difference between the centrifuge discharge volume M and the discharge volume target value m is large, and to make small adjustments to the feed regulating valve 14 with a longer adjustment time interval when the difference between the centrifuge discharge volume M and the discharge volume target value m is small.
[0021] Preferably, the control module 34 is configured to, when 0%m≤M<50%m, control the feed regulating valve 14 to open at an amplitude of 5%-10% of the total stroke each time, with an interval of 3-5 seconds between each execution. When 50%m≤M<75%m, control the feed regulating valve 14 to open at an amplitude of 3%-5% of the total stroke each time, with an interval of 3-5 seconds between each execution. When 75%m≤M<90%m, control the feed regulating valve 14 to open at an amplitude of 1.5%-3% of the total stroke each time, with an interval of 3-5 seconds between each execution. When 90%m≤M<95%m, control the feed regulating valve 14 to open at an amplitude of 0.5%-1.5% of the total stroke each time, with an interval of 5-10 seconds between each execution.
[0022] When 95%m≤M<99%m, the feed regulating valve 14 is controlled to open at an amplitude of 0.1%-0.5% of the total stroke each time, with an interval of 10-20 seconds between each execution. When 99%m≤M<100%m, the feed regulating valve 14 is controlled to open at an amplitude of 0.05%-0.1% of the total stroke each time, with an interval of 30-60 seconds between each execution. When 100%m<M<101%m, the feed regulating valve 14 is controlled to open at an amplitude of 0.05%-0.1% of the total stroke each time, with an interval of 30-60 seconds between each execution. When 101%m≤M<105%m, the feed regulating valve 14 is controlled to close at an amplitude of 0.1%-0.5% of the total stroke each time, with an interval of 10-20 seconds between each execution.
[0023] When 105%m≤M<110%m, the feed regulating valve 14 is controlled to be closed at a range of 0.5%-1.5% of the total stroke each time, with an interval of 5-10 seconds between each execution. When 110%m≤M<125%m, the feed regulating valve 14 is controlled to be closed at a range of 1.5%-3% of the total stroke each time, with an interval of 3-5 seconds between each execution. When 125%m≤M<150%m, the feed regulating valve 14 is controlled to be closed at a range of 3%-5% of the total stroke each time, with an interval of 3-5 seconds between each execution. When 150%m≤M, the feed regulating valve 14 is controlled to be closed at a range of 5%-10% of the total stroke each time, with an interval of 3-5 seconds between each execution.
[0024] Preferably, the judgment module 35 is further configured to determine whether the opening of the feed regulating valve 14 has reached its maximum value when the centrifuge discharge volume M is less than the discharge volume target value m. The alarm module 33 is further configured to issue an alarm when the centrifuge discharge volume M is less than the discharge volume target value m and the opening of the feed regulating valve 14 has reached its maximum value.
[0025] The present invention gradually reduces the opening of the feed regulating valve 14 when the centrifuge discharge volume M is greater than the discharge volume target value m, and gradually increases the opening of the feed regulating valve 14 when the centrifuge discharge volume M is less than the discharge volume target value m, so that the centrifuge discharge volume approaches or is equal to the discharge volume target value m, thereby achieving controllable centrifuge discharge volume.
[0026] It is set that when the difference between the centrifuge discharge volume M and the discharge volume target value m is large, the feed regulating valve 14 is adjusted significantly and the adjustment time interval is short. When the difference between the centrifuge discharge volume M and the discharge volume target value m is small, the feed regulating valve 14 is adjusted slightly and the adjustment time interval is long. This can make the centrifuge discharge volume M quickly adjusted to the discharge volume target value m, making the control of the centrifuge discharge volume M faster and more accurate.
[0027] The present invention can prevent the influence of factors such as the change of screen aperture, material particle size and viscosity on the discharge amount of the centrifuge, so that the centrifuge can output materials according to the preset amount, thereby enabling the subsequent production process and operating parameters to be accurately adjusted to accurately meet the requirements of process production, ensure product quality and improve production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS
[0028] Figure 1 . Schematic diagram of quantitative control system of material conveying system; Figure 2 . Schematic diagram of the internal structure of the centrifuge; Figure 3 .Flowchart of quantitative control method of material conveying system; Figure 4 .Connection structure diagram of quantitative control system of material conveying system.
[0029] In the figure, 1. Conveying system, 11. Mixing equipment, 12. Conveying equipment, 13. Thickener, 14. Feed regulating valve 14, 15. Slurry concentration meter, 16. Slurry flow meter, 17. Filtrate concentration meter, 18. Filtrate flow meter, 19. Slurry liquid phase concentration meter, 2. Centrifuge, 21. Spiral scraper, 22. Screen, 23. Drain port, 24. Discharge port, 3. Controller, 31. Filtration rate calculation module, 32. Discharge volume calculation module, 33. Alarm module, 34. Control module, 35. Judgment module. DETAILED DESCRIPTION
[0030] The preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings.
[0031] like Figure 1 As shown, when transporting carnallite ore, a conveying system 1 is usually used for transportation. First, the material and solution are added to the mixing device 11 for mixing to form a solid-liquid mixture, that is, the material slurry. The material slurry is transported to the concentration adjustment equipment such as the thickener 13 through the conveying device 12 for processing.
[0032] The material slurry is separated into an overflow dilute phase and an underflow thick phase by the thickener 13. After the overflow dilute phase is simply filtered, the concentration value measured by the slurry liquid phase concentration meter 19 is used as the concentration value of the feed slurry liquid phase.
[0033] When the solid-liquid ratio of the underflow thick phase reaches the optimal feed concentration for centrifuge 2, it is fed into centrifuge 2 as feed slurry for solid-liquid separation. After processing in centrifuge 2, a solid phase filter cake containing a small amount of liquid entrainment and a centrifuge filtrate containing a small amount of solid phase are obtained.
[0034] The centrifuge 2 is provided with a slurry concentration meter 15 , a slurry flow meter 16 , a filtrate concentration meter 17 and a filtrate flow meter 18 .
[0035] The slurry concentration meter 15 can detect the concentration of the feed slurry entering the centrifuge, the slurry flow meter 16 can detect the flow rate of the feed slurry entering the centrifuge, the filtrate concentration meter 17 can detect the concentration of the filtrate discharged from the centrifuge, and the filtrate flow meter 18 can detect the flow rate of the filtrate discharged from the centrifuge.
[0036] like Figure 2 As shown, when the centrifuge 2 is running, the spiral scraper 21 rotates, and the potassium chloride slurry enters the small diameter end of the feed cone, and is evenly distributed between the spiral scraper 21 and the screen 22 through the discharge port by centrifugal action. Under the action of centrifugal force, the liquid phase in the slurry passes through the screen 22 and is discharged from the discharge port 23, and the solid phase in the slurry is retained on the screen 22. With the help of the inclination angle of the screen 22 and the differential speed of the spiral scraper 21, the material is transferred from the small diameter end of the screen 22 to the large diameter end and discharged from the discharge port 24.
[0037] The centrifuge 2 is provided with a feed regulating valve 1414 for controlling the feed speed and an alarm for issuing an alarm.
[0038] The centrifuge 2 is equipped with a temperature sensor, a current sensor, a voltage sensor, a speed sensor and an oil pressure sensor, etc., which are used to detect the equipment operating parameters such as the temperature value, current value, voltage value, speed value and oil pressure value of the centrifuge 2 when it is working.
[0039] The centrifuge 2 is also provided with a feed slurry concentration meter 15 , a feed slurry flow meter 16 , a filtrate concentration meter 17 and a filtrate flow meter 18 .
[0040] The feed slurry concentration meter 15 is used to measure the feed slurry concentration value, the feed slurry flow meter 16 is used to measure the feed slurry flow value, the filtrate concentration meter 17 is used to measure the filtrate concentration value discharged from the centrifuge, and the filtrate flow meter 18 is used to measure the filtrate flow value discharged from the centrifuge.
[0041] like Figure 3 As shown, the quantitative control method of the material conveying system includes a target value setting step S1, in which the controller 3 sets the discharge amount target value m and the filtration rate target value t.
[0042] In the equipment status detection step S2, the controller detects the operating status of the centrifuge according to the operating parameters of the centrifuge 2, such as the temperature value, current value, voltage value, speed value and oil pressure value. When the operating parameters of the centrifuge are normal, the process proceeds to the parameter acquisition step S3. Otherwise, the centrifuge fails, a fault alarm is issued, and the feed regulating valve 14 is closed.
[0043] In the parameter acquisition step S3, the controller 3 receives the feed slurry concentration value, the feed slurry flow value, the filtrate concentration value, the filtrate flow value, and the feed slurry liquid phase concentration value.
[0044] In calculation step S4, the controller 3 calculates the centrifuge penetration rate T according to the feed slurry concentration value, the feed slurry flow value, the filtrate concentration value, the filtrate flow value, and the feed slurry liquid phase concentration value. The calculation formula is as follows: Centrifuge penetration rate ; The centrifuge discharge volume M is calculated based on the feed slurry concentration value, feed slurry flow value, filtrate concentration value and filtrate flow value. The calculation formula is as follows: Centrifuge discharge capacity M= 1×Q1 - 2×Q2 in, 1 is the feed slurry concentration value, Q1 is the feed slurry flow value, 2 is the filtrate concentration value, Q2 is the filtrate flow value, 3 is the feed slurry liquid phase concentration value.
[0045] In the filtration rate comparison step S5, the controller 3 compares the filtration rate T of the heart machine with the filtration rate target value t to obtain a comparison result.
[0046] When the centrifuge filtration rate T is greater than or equal to the filtration rate target value t, the alarm module 33 outputs a filtration limit alarm to remind you to replace the centrifuge screen. When the centrifuge filtration rate T is less than the filtration rate target value t, the process goes to step 6 S6.
[0047] In the discharge control step S6, the controller 3 compares the centrifuge discharge volume M with the discharge volume target value m to obtain a comparison result.
[0048] When the discharge volume M of the centrifuge is greater than the target discharge volume m, the opening of the feed regulating valve 14 is gradually reduced, and the process returns to the parameter acquisition step S3.
[0049] When the centrifuge discharge volume M is equal to the discharge volume target value m, the opening of the feed regulating valve 14 is not adjusted, and the process returns to the parameter acquisition step S3.
[0050] When the centrifuge discharge volume M is less than the discharge volume target value m, it is determined whether the opening of the feed regulating valve 14 has reached the maximum value. When the opening of the feed regulating valve 14 has reached the maximum value, an alarm is issued. Otherwise, the opening of the feed regulating valve 14 is gradually increased, and the process returns to the parameter acquisition step S3.
[0051] Among them, when the difference between the centrifuge discharge volume M and the discharge volume target value m is large, the feed regulating valve 14 is adjusted significantly and the adjustment time interval is short. When the difference between the centrifuge discharge volume M and the discharge volume target value m is small, the feed regulating valve 14 is adjusted slightly and the adjustment time interval is long.
[0052] In this embodiment, when the difference between the centrifuge discharge volume M and the discharge volume target value m is different, the control method of the feed regulating valve 14 is: When 0%m≤M<50%m, the feed regulating valve 14 is opened at an amplitude of 5%-10% of the total stroke each time, and the interval between each execution is 3-5 seconds.
[0053] When 50%m≤M<75%m, the feed regulating valve 14 is opened at an amplitude of 3%-5% of the total stroke each time, and the interval between each execution is 3-5 seconds.
[0054] When 75%m≤M<90%m, the feed regulating valve 14 is opened at an amplitude of 1.5%-3% of the total stroke each time, and the interval between each execution is 3-5 seconds.
[0055] When 90%m≤M<95%m, the feed regulating valve 14 is opened at a range of 0.5%-1.5% of the total stroke each time, and the interval between each execution is 5-10 seconds.
[0056] When 95%m≤M<99%m, the feed regulating valve 14 is opened at a range of 0.1%-0.5% of the total stroke each time, and the interval between each execution is 10-20 seconds.
[0057] When 99%m≤M<100%m, the feed regulating valve 14 is opened at a range of 0.05%-0.1% of the total stroke each time, and the interval between each execution is 30-60 seconds.
[0058] When 100%m<M<101%m, the feed regulating valve 14 is opened at an amplitude of 0.05%-0.1% of the total stroke each time, and the interval between each execution is 30-60 seconds.
[0059] When 101%m≤M<105%m, the feed regulating valve 14 is closed at a range of 0.1%-0.5% of the total stroke each time, and the interval between each execution is 10-20 seconds.
[0060] When 105%m≤M<110%m, the feed regulating valve 14 is closed at a range of 0.5%-1.5% of the total stroke each time, and the interval between each execution is 5-10 seconds.
[0061] When 110%m≤M<125%m, the feed regulating valve 14 is closed at a range of 1.5%-3% of the total stroke each time, and the interval between each execution is 3-5 seconds.
[0062] When 125%m≤M<150%m, the feed regulating valve 14 is closed at an amplitude of 3%-5% of the total stroke each time, and the interval between each execution is 3-5 seconds.
[0063] When 150%m≤M, the feed regulating valve 14 is closed at an amplitude of 5%-10% of the total stroke each time, and the interval between each execution is 3-5 seconds.
[0064] like Figure 4 As shown, the quantitative control system of the material conveying system includes a controller 3, which includes a filtration rate calculation module 31, a discharge amount calculation module 32, a judgment module 35, an alarm module 33 and a control module 34. The controller 3 obtains the feed slurry concentration value, the feed slurry flow value, the filtrate concentration value, the filtrate flow value and the feed slurry liquid phase concentration value.
[0065] The centrifuge penetration rate calculation module 31 calculates the centrifuge penetration rate T according to the feed slurry concentration value, feed slurry flow value, filtrate concentration value, filtrate flow value and feed slurry liquid phase concentration value. The calculation formula is: Centrifuge discharge capacity M= 1×Q1 - 2×Q2 The discharge amount calculation module 32 is used to calculate the centrifuge discharge amount M according to the feed slurry concentration value, the feed slurry flow value, the filtrate concentration value and the filtrate flow value.
[0066] The calculation formula for the centrifuge discharge volume M is: Centrifuge penetration rate ; in, 1 is the feed slurry concentration value, Q1 is the feed slurry flow value, 2 is the filtrate concentration value, Q2 is the filtrate flow value, 3 is the feed slurry liquid phase concentration value.
[0067] The judgment module 35 is used to compare the centrifuge filtration rate T with the filtration rate target value t, and compare the centrifuge discharge volume M with the discharge volume target value m; when the centrifuge discharge volume M is less than the discharge volume target value m, it is judged whether the opening of the feed regulating valve 14 reaches the maximum value.
[0068] The alarm module 33 is used to issue an alarm when the centrifuge discharge volume M is less than the discharge volume target value m and the opening of the feed regulating valve 14 reaches the maximum value; when the centrifuge fails, a fault alarm is issued; when the centrifuge filtration rate T is greater than or equal to the filtration rate target value t, an over-limit filtration alarm is output to remind the centrifuge screen to be replaced.
[0069] The control module 34 is used to close the feed regulating valve 14 when a centrifuge malfunctions; when the centrifuge discharge volume M is greater than the discharge volume target value m, gradually reduce the opening of the feed regulating valve 14; when the centrifuge discharge volume M is less than the discharge volume target value m, gradually increase the opening of the feed regulating valve 14; when the centrifuge discharge volume M is equal to the discharge volume target value m, do not adjust the opening of the feed regulating valve 14.
[0070] When the difference between the centrifuge discharge volume M and the discharge volume target value m is large, the feed regulating valve 14 is adjusted significantly, and the adjustment time interval is short. When the difference between the centrifuge discharge volume M and the discharge volume target value m is small, the feed regulating valve 14 is adjusted slightly, and the adjustment time interval is long.
[0071] In this embodiment, when the difference between the centrifuge discharge volume M and the discharge volume target value m is different, the control module 34 controls the feed regulating valve 14 in the following manner: When 0%m≤M<50%m, the feed regulating valve 14 is controlled to open at an amplitude of 5%-10% of the total stroke each time, and the interval between each execution is 3-5 seconds. When 50%m≤M<75%m, the feed regulating valve 14 is controlled to open at an amplitude of 3%-5% of the total stroke each time, and the interval between each execution is 3-5 seconds. When 75%m≤M<90%m, the feed regulating valve 14 is controlled to open at an amplitude of 1.5%-3% of the total stroke each time, and the interval between each execution is 3-5 seconds. When 90%m≤M<95%m, the feed regulating valve 14 is controlled to open at an amplitude of 0.5%-1.5% of the total stroke each time, and the interval between each execution is 5-10 seconds.
[0072] When 95%m≤M<99%m, the feed regulating valve 14 is controlled to open at an amplitude of 0.1%-0.5% of the total stroke each time, with an interval of 10-20 seconds between each execution. When 99%m≤M<100%m, the feed regulating valve 14 is controlled to open at an amplitude of 0.05%-0.1% of the total stroke each time, with an interval of 30-60 seconds between each execution. When 100%m<M<101%m, the feed regulating valve 14 is controlled to open at an amplitude of 0.05%-0.1% of the total stroke each time, with an interval of 30-60 seconds between each execution. When 101%m≤M<105%m, the feed regulating valve 14 is controlled to close at an amplitude of 0.1%-0.5% of the total stroke each time, with an interval of 10-20 seconds between each execution.
[0073] When 105%m≤M<110%m, the feed regulating valve 14 is controlled to be closed at a range of 0.5%-1.5% of the total stroke each time, with an interval of 5-10 seconds between each execution. When 110%m≤M<125%m, the feed regulating valve 14 is controlled to be closed at a range of 1.5%-3% of the total stroke each time, with an interval of 3-5 seconds between each execution. When 125%m≤M<150%m, the feed regulating valve 14 is controlled to be closed at a range of 3%-5% of the total stroke each time, with an interval of 3-5 seconds between each execution. When 150%m≤M, the feed regulating valve 14 is controlled to be closed at a range of 5%-10% of the total stroke each time, with an interval of 3-5 seconds between each execution.
[0074] The present invention gradually reduces the opening of the feed regulating valve 14 when the centrifuge discharge volume M is greater than the discharge volume target value m; and gradually increases the opening of the feed regulating valve 14 when the centrifuge discharge volume M is less than the discharge volume target value m, so that the centrifuge discharge volume approaches or is equal to the discharge volume target value m, thereby achieving controllable centrifuge discharge volume.
[0075] It is set that when the difference between the centrifuge discharge volume M and the discharge volume target value m is large, the feed regulating valve 14 is adjusted significantly and the adjustment time interval is short. When the difference between the centrifuge discharge volume M and the discharge volume target value m is small, the feed regulating valve 14 is adjusted slightly and the adjustment time interval is long. This can make the centrifuge discharge volume M quickly adjusted to the discharge volume target value m, making the control of the centrifuge discharge volume M faster and more accurate.
[0076] The present invention can prevent the influence of factors such as the change of screen mesh aperture, material particle size and viscosity on the centrifuge discharge volume M, so that the centrifuge can output materials according to a preset amount, thereby enabling the subsequent production process and operating parameters to be accurately adjusted to accurately meet the requirements of process production, ensure product quality and improve production efficiency.
[0077] It should be noted that the above embodiments are intended to illustrate rather than limit the present invention.
Claims
1. A quantitative control method for a material conveying system, characterized in that: include, Target value setting step (S1), setting a target value m for discharge volume and a target value t for filtration rate; Parameter acquisition step (S3), acquiring the feed slurry concentration value, feed slurry flow value, filtrate concentration value, filtrate flow value and feed slurry liquid phase concentration value; Calculation step (S4), calculating the centrifuge filtration rate T and the centrifuge discharge volume M; The filtration rate comparison step (S5) compares the centrifuge filtration rate T with the filtration rate target value t. When the centrifuge filtration rate T is greater than or equal to the filtration rate target value t, an over-limit filtration alarm is output to remind the centrifuge screen to be replaced. When the centrifuge penetration rate T is less than the target penetration rate value t, the process proceeds to the discharge control step (S6); The discharge control step (S6) compares the centrifuge discharge amount M with the discharge amount target value m. When the centrifuge discharge amount M is greater than the discharge amount target value m, the opening of the feed regulating valve (14) is gradually reduced, and the process returns to the parameter acquisition step (S3). When the centrifuge discharge volume M is equal to the discharge volume target value m, the opening of the feed regulating valve (14) is not adjusted, and the process returns to the parameter acquisition step (S3); When the discharge volume M of the centrifuge is less than the target discharge volume m, the opening of the feed regulating valve (14) is gradually increased, and the process returns to the parameter acquisition step (S3).
2. The quantitative control method of the material conveying system according to claim 1, characterized in that: In the calculation step (S4), Centrifuge discharge capacity M= 1×Q1 - 2×Q2 Centrifuge penetration rate ; in, 1 is the feed slurry concentration value, Q1 is the feed slurry flow value, 2 is the filtrate concentration value, Q2 is the filtrate flow value, 3 is the feed slurry liquid phase concentration value.
3. The quantitative control method of the material conveying system according to claim 2, characterized in that: In the discharging control step (S6), When the difference between the centrifuge discharge volume M and the discharge volume target value m is large, the opening of the feed regulating valve (14) is adjusted to a large extent, and the adjustment time interval is short; When the difference between the centrifuge discharge volume M and the discharge volume target value m is small, the opening of the feed regulating valve (14) is adjusted to a smaller extent, and the adjustment time interval is longer.
4. The quantitative control method of the material conveying system according to claim 3, characterized in that: In the discharging control step (S6), When 0%m≤M<50%m, the feed regulating valve (14) is opened at an amplitude of 5%-10% of the total stroke each time, and the interval between each execution is 3-5 seconds; When 50%m≤M<75%m, the feed regulating valve (14) is opened at a range of 3%-5% of the total stroke each time, and the interval between each operation is 3-5 seconds; When 75%m≤M<90%m, the feed regulating valve (14) is opened at a range of 1.5%-3% of the total stroke each time, and the interval between each execution is 3-5 seconds; When 90%m≤M<95%m, the feed regulating valve (14) is opened at a range of 0.5%-1.5% of the total stroke each time, and the interval between each execution is 5-10 seconds; When 95%m≤M<99%m, the feed regulating valve (14) is opened at a range of 0.1%-0.5% of the total stroke each time, and the interval between each execution is 10-20 seconds; When 99%m≤M<100%m, the feed regulating valve (14) is opened at a range of 0.05%-0.1% of the total stroke each time, and the interval between each execution is 30-60 seconds; When 100%m<M<101%m, the feed regulating valve (14) is opened at a range of 0.05%-0.1% of the total stroke each time, and the interval between each execution is 30-60 seconds; When 101%m≤M<105%m, the feed regulating valve (14) is closed at a range of 0.1%-0.5% of the total stroke each time, and the interval between each execution is 10-20 seconds; When 105%m≤M<110%m, the feed regulating valve (14) is closed at a range of 0.5%-1.5% of the total stroke each time, and the interval between each execution is 5-10 seconds; When 110%m≤M<125%m, the feed regulating valve (14) is closed at a rate of 1.5%-3% of the total stroke each time, with an interval of 3-5 seconds between each execution; When 125%m≤M<150%m, the feed regulating valve (14) is closed at a range of 3%-5% of the total stroke each time, and the interval between each execution is 3-5 seconds; When 150%m≤M, the feed regulating valve (14) is closed at an amplitude of 5%-10% of the total stroke each time, and the interval between each execution is 3-5 seconds.
5. The quantitative control method of the material conveying system according to claim 4, characterized in that: In the discharge control step (S6), when the discharge amount M of the centrifuge is less than the discharge amount target value m, it also includes judging whether the opening of the feed regulating valve (14) has reached the maximum value. When the opening of the feed regulating valve (14) has reached the maximum value, an alarm is issued. Otherwise, the feed regulating valve (14) is gradually opened and the process returns to the parameter acquisition step (S3).
6. Material conveying system quantitative control system, characterized in that, The controller (3) includes a filtration rate calculation module (31), a discharge amount calculation module (32), a judgment module (35), an alarm module (33) and a control module (34). The controller (3) obtains the feed slurry concentration value, the feed slurry flow value, the filtrate concentration value, the filtrate flow value and the feed slurry liquid phase concentration value; The filtration rate calculation module (31) is used to calculate the centrifuge filtration rate T according to the feed slurry concentration value, the feed slurry flow value, the filtrate concentration value, the filtrate flow value and the feed slurry liquid phase concentration value; The discharge amount calculation module (32) is used to calculate the centrifuge discharge amount M according to the feed slurry concentration value, the feed slurry flow value, the filtrate concentration value and the filtrate flow value; The judgment module (35) is used to compare the centrifuge filtration rate T with the filtration rate target value t, and to compare the centrifuge discharge volume M with the discharge volume target value m; The control module (34) is used to close the feed regulating valve (14) when a centrifuge malfunctions; when the centrifuge discharge volume M is greater than the discharge volume target value m, gradually reduce the opening of the feed regulating valve (14); when the centrifuge discharge volume M is less than the discharge volume target value m, gradually increase the opening of the feed regulating valve (14); when the centrifuge discharge volume is equal to the discharge volume target value m, do not adjust the opening of the feed regulating valve (14); The alarm module (33) is used to issue a fault alarm when a centrifuge fails, and output a filtration limit exceeding alarm when the centrifuge filtration rate T is greater than or equal to the filtration rate target value t, prompting a centrifuge screen to be replaced.
7. The quantitative control system of the material conveying system according to claim 6, characterized in that: The filtration rate calculation module (31) is used to calculate the centrifuge filtration rate according to the following formula , Centrifuge discharge capacity M= 1×Q1 - 2×Q2 The discharge amount calculation module (32) is used to calculate the discharge amount M of the centrifuge according to the following formula: Centrifuge penetration rate ; in, 1 is the feed slurry concentration value, Q1 is the feed slurry flow value, 2 is the filtrate concentration value, Q2 is the filtrate flow value, 3 is the feed slurry liquid phase concentration value.
8. The quantitative control system of the material conveying system according to claim 7, characterized in that: The control module (34) is used to adjust the feed regulating valve (14) significantly when the difference between the centrifuge discharge volume M and the discharge volume target value m is large, and the adjustment time interval is short; and to adjust the feed regulating valve (14) slightly when the difference between the centrifuge discharge volume M and the discharge volume target value m is small, and the adjustment time interval is long.
9. The quantitative control system of the material conveying system according to claim 8, characterized in that: The control module (34) is used to control the feed regulating valve (14) to open at an amplitude of 5%-10% of the total stroke each time when 0%m≤M<50%m, with each execution interval of 3-5 seconds; When 50%m≤M<75%m, the feed regulating valve (14) is controlled to open at an amplitude of 3%-5% of the total stroke each time, and the interval between each execution is 3-5 seconds; When 75%m≤M<90%m, the feed regulating valve (14) is controlled to open at a range of 1.5%-3% of the total stroke each time, with an interval of 3-5 seconds between each execution; When 90%m≤M<95%m, the feed regulating valve (14) is controlled to open at a range of 0.5%-1.5% of the total stroke each time, with an interval of 5-10 seconds between each execution; When 95%m≤M<99%m, the feed regulating valve (14) is controlled to open at a range of 0.1%-0.5% of the total stroke each time, with an interval of 10-20 seconds between each execution; When 99%m≤M<100%m, the feed regulating valve (14) is controlled to open at a range of 0.05%-0.1% of the total stroke each time, and the interval between each execution is 30-60 seconds; When 100%m<M<101%m, the feed regulating valve (14) is controlled to open at a range of 0.05%-0.1% of the total stroke each time, and the interval between each execution is 30-60 seconds; When 101%m≤M<105%m, the feed regulating valve (14) is controlled to close at a range of 0.1%-0.5% of the total stroke each time, and the interval between each execution is 10-20 seconds; When 105%m≤M<110%m, the feed regulating valve (14) is controlled to close at a range of 0.5%-1.5% of the total stroke each time, and the interval between each execution is 5-10 seconds; When 110%m≤M<125%m, the feed regulating valve (14) is controlled to close at a range of 1.5%-3% of the total stroke each time, and the interval between each execution is 3-5 seconds; When 125%m≤M<150%m, the feed regulating valve (14) is controlled to close at a range of 3%-5% of the total stroke each time, and the interval between each execution is 3-5 seconds; When 150%m≤M, the feed regulating valve (14) is controlled to close at an amplitude of 5%-10% of the total stroke each time, and the interval between each execution is 3-5 seconds.
10. The quantitative control system of the material conveying system according to claim 9, characterized in that: The judgment module (35) is also used to judge whether the opening of the feed regulating valve (14) reaches the maximum value when the discharge amount M of the centrifuge is less than the discharge amount target value m; The alarm module (33) is also used to issue an alarm when the centrifuge discharge volume M is less than the discharge volume target value m and the opening of the feed regulating valve (14) reaches the maximum value.