A control method for a pressure filtration system

Abstract

This invention relates to the field of solid-liquid separation technology, and more particularly to a control method for a pressure filtration system. The method includes: S2: controlling the pressure filtration system to perform a set of discharges according to current operating parameters; obtaining the product moisture value under the current operating parameters; S3: determining whether the product moisture value is within a set range; if yes, proceeding to step S4; S4: increasing the filtration pressure to a specified pressure; S5: controlling the pressure filtration system to perform a set of discharges according to current operating parameters; obtaining the energy consumption change range; S6: determining whether the energy consumption change range is less than a set range value; if yes, returning to step S5; if the energy consumption change range is greater than the set range value and the energy consumption value decreases, returning to step S3. This method correlates the product moisture value, filtration pressure, and energy consumption value, and adjusts the filtration pressure in real time according to the product moisture value and energy consumption change range, adjusting the pressure operation to the optimal and most energy-efficient state.

Description

Technical Field

[0001] This invention relates to the field of solid-liquid separation technology, and in particular to a control method for a pressure filtration system. Background Technology

[0002] As one of the world's most advanced solid-liquid separation technologies, the pressure filter's main function is solid-liquid separation, and it is widely used in coal and cement separation. During operation, the pressure filter uses compressed air within a container to create positive pressure filtration, trapping solid particles from the suspension on the filter disc to form a filter cake, while simultaneously allowing the liquid to pass through the filter medium and be discharged, thus achieving effective solid-liquid separation.

[0003] Compared to other types of filter presses, current pressure filters have higher energy consumption and lower levels of automation. Numerous parameters affect the production performance of pressure filters, and currently, these key parameters still rely on manual adjustment. The effectiveness of these adjustments depends solely on human experience, and the adjustment process only considers output and feed moisture content, neglecting equipment energy consumption. This results in significant energy waste even under optimal parameters. Summary of the Invention

[0004] The first objective of this invention is to provide a control method for a pressurized filtration system to solve the technical problem in the prior art where energy consumption cannot be accurately controlled during the pressurized filtration process, resulting in energy waste.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A control method for a pressure filtration system includes the following steps: S2: Control the pressure filtration system to perform a set of discharges according to the current operating parameters; Get the product moisture content under the current operating parameters; S3: Determine whether the moisture content of the product is within the set range; if so, proceed to step S4. S4: Increase the filtration pressure to the specified pressure; S5: Control the pressure filtration system to perform a set of discharges according to the current operating parameters; Obtain the energy consumption change rate, which is the absolute value of the difference between the energy consumption value of the current set of material discharges and the energy consumption value of the previous set of material discharges; obtain the product moisture value under the current operating parameters; S6: Determine whether the energy consumption change is less than a set value; If so, return to step S5; If the change in energy consumption is greater than the set value and the energy consumption decreases, then return to step S3.

[0006] Furthermore, step S3 also includes: if the moisture content of the product is less than a set range, then proceed to step S7; Step S7 includes: Get the feed concentration under the current operating parameters; Determine whether the feed concentration is less than the set upper limit; if so, increase the feed concentration to the specified concentration; if not, decrease the filtration pressure to the specified pressure. Then return to step S2.

[0007] Furthermore, step S3 also includes: if the moisture content of the product is greater than a set range, then proceed to step S8; Step S8 includes: Get the feed concentration under the current operating parameters; Determine whether the feed concentration is greater than the set lower limit; if yes, reduce the feed concentration to the specified concentration; if no, increase the filtration pressure to the specified pressure. Then return to step S2.

[0008] Furthermore, step S6 also includes: determining whether the moisture content of the product is within a set range; If the change in energy consumption is less than the set value and the moisture content of the product is within the set range, then return to step S5; If the moisture content of the product is less than the set range, proceed to step S7; If the moisture content of the product is greater than the set range, proceed to step S8.

[0009] Furthermore, step S6 also includes: if the energy consumption change is greater than a set value and the energy consumption increases, then proceed to step S9; Step S9 includes: reducing the filtration pressure to a specified pressure, and then returning to step S2.

[0010] Furthermore, the energy consumption value is the amount of low-pressure air consumed.

[0011] A second objective of this invention is to provide a pressure filtration system, comprising a pressure filter, a blower, a gas flow meter, a moisture meter, and a control center module, wherein: A pressure regulating valve is installed at the low-pressure air inlet of the pressurization chamber of the pressurized filter, and the blower is connected to the low-pressure air inlet through a pipeline; a gas flow meter is installed on the pipeline between the pressurized filter and the blower; the moisture meter is used to detect the moisture value of the product; the pressure regulating valve, the gas flow meter and the moisture meter are all electrically connected to the control center module.

[0012] Furthermore, it also includes a feed tank for storing the solid-liquid mixture to be filtered, the feed tank being connected to the pressure filter via a pipeline; The feed tank is equipped with a concentration meter and / or a level gauge.

[0013] Furthermore, it also includes a deep cone thickener, the bottom of which is connected to the feed tank via an underflow pump; the underflow pump is connected to a frequency converter.

[0014] Furthermore, the pressure filter is equipped with an upper filtrate valve and a lower filtrate valve at the upper filtrate port and the lower filtrate port, respectively; And / or, the pressure filter is equipped with a level gauge.

[0015] The beneficial effects of this invention are: This invention provides a control method and a pressurized filtration system for a pressurized filtration system. The method includes: S2: controlling the pressurized filtration system to perform a set of discharges according to the current operating parameters; obtaining the moisture value of the product under the current operating parameters; S3: determining whether the moisture value of the product is within a set range; if so, proceeding to step S4; S4: increasing the filtration pressure to a specified pressure; S5: controlling the pressurized filtration system to perform a set of discharges according to the current operating parameters; obtaining the energy consumption change range; S6: determining whether the energy consumption change range is less than a set range value; if so, returning to step S5; if the energy consumption change range is greater than the set range value and the energy consumption value decreases, returning to step S3.

[0016] The control method of the pressurized filtration system provided in this application correlates the product moisture value, filtration pressure and energy consumption value, and adjusts the filtration pressure in real time according to the changes in product moisture value and energy consumption, so as to adjust the pressurized operation to the optimal and most energy-efficient state. Attached Figure Description

[0017] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 A flowchart illustrating the control method of the pressurized filtration system provided in this embodiment of the invention. Figure 1 ; Figure 2 A flowchart illustrating the control method of the pressurized filtration system provided in this embodiment of the invention. Figure 2 ; Figure 3 A flowchart illustrating the control method of the pressurized filtration system provided in this embodiment of the invention. Figure 3 ; Figure 4 This is a schematic diagram of the pressurized filtration system provided in an embodiment of the present invention.

[0019] icon: 1- Pressure filter; 11- Pressure regulating valve; 12- Upper filtrate valve; 13- Lower filtrate valve; 14- Level gauge; 2- Blower; 3- Gas flow meter; 4- Moisture meter; 5- Control center module; 6- Feed tank; 61- Concentration meter; 62- Level gauge; 63- Feed pump; 7- Deep cone thickener; 71- Underflow pump; 72- Frequency converter; 8- Discharge belt; 9- Gas storage tank. Detailed Implementation

[0020] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] It should be noted that in the description of this invention, the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0022] It should be noted that in the description of this invention, the terms "connection" and "installation" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or a connection through an intermediate medium; they can refer to a mechanical connection or an electrical connection. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0023] Currently, the key parameters of pressure filters during operation rely on manual adjustment. The adjustment effect depends solely on the experience of personnel, and the adjustment process only considers output and moisture content of the feed material, resulting in significant energy waste even under optimal parameters.

[0024] Based on this, the applicant discovered through research that there is a correlation between the energy consumption, filtration pressure and moisture content of the product in a pressure filter. Increasing the filtration pressure will reduce energy consumption and moisture content of the product within a certain range, while also increasing output within a certain range.

[0025] Based on the above research findings, this invention provides a control method for a pressurized filtration system, referring to... Figure 1 The method includes the following steps: S2: Control the pressure filtration system to perform a set of discharges according to the current operating parameters; Get the product moisture content under the current operating parameters; S3: Determine whether the moisture content of the product is within the set range; if so, proceed to step S4. S4: Increase the filtration pressure to the specified pressure; S5: Control the pressure filtration system to perform a set of discharges according to the current operating parameters; Obtain the energy consumption change rate, which is the absolute value of the difference between the energy consumption value of the current set of material discharges and the energy consumption value of the previous set of material discharges; obtain the product moisture value under the current operating parameters; S6: Determine whether the energy consumption change is less than a set value; If the change in energy consumption is less than the set value, then return to step S5; If the change in energy consumption is greater than the set value and the energy consumption decreases, then return to step S3.

[0026] The control method of the pressurized filtration system provided by this invention increases the filtration pressure when the moisture content of the feed material is within a set range. This reduces energy consumption, achieving energy saving, and also lowers the moisture content of the feed material, keeping it within the required range and improving both the quality and yield of the feed material. When the change in energy consumption is less than the set value, meaning that further increasing the filtration pressure has little impact on energy consumption, the filtration pressure is stopped, and the system maintains the current operating pressure while continuously monitoring relevant parameters, achieving dynamic adjustment.

[0027] The method provided in this application correlates the product moisture content, filtration pressure, and energy consumption. During system operation, it continuously monitors the product moisture content and energy consumption, and adjusts the filtration pressure in real time based on changes in these values ​​to maintain an optimal pressure. Under this optimal pressure, the pressurized filtration system can ensure both product moisture content and output are at good levels without wasting energy, thus adjusting the pressurization operation to its optimal and most energy-efficient state.

[0028] Furthermore, step S6 also includes: determining whether the moisture content of the product under the current operating parameters is within the set range; If the change in energy consumption is less than the set value and the moisture content of the product is within the set range, then return to step S5.

[0029] The control method provided in this embodiment continuously monitors the moisture content of each batch of discharged material during system operation, thereby ensuring that all parameters are always in an optimal state of dynamic equilibrium.

[0030] The applicant's research also found that the energy consumption of the pressure filtration system mainly comes from the consumption of low-pressure air. This is because: the existing pressure filter 1 is equipped with a pressure chamber and a filter disc. The pressure chamber is used to apply filtration pressure to the solid-liquid mixture to force the liquid out of the mixture through the filter disc, while the solid particles are trapped on the filter disc to form a filter cake. During system operation, low-pressure air in the pressure chamber passes through the filter cake and filter disc to dry the filter cake. While drying, the air also escapes outward. Therefore, low-pressure air needs to be continuously input into the pressure chamber to maintain a stable filtration pressure inside the pressure chamber, which makes the consumption of low-pressure air the main energy consumption of the pressure filtration system.

[0031] Based on the above research findings, in this embodiment, the energy consumption value is the amount of low-pressure air consumed.

[0032] Further research revealed that increasing the filtration pressure within a certain range correspondingly reduces the low-pressure air volume consumed per unit mass of output. This is because: during the operation of the pressure filter 1, the filter disc rotates under the drive of the main shaft. When the filter disc rotates and descends below the liquid surface of the solid-liquid mixture, solid particles are trapped on the filter disc to form a filter cake. When the filter disc rotates and rises above the liquid surface of the solid-liquid mixture, the filter cake also rises synchronously with the filter disc. After the filter cake rises above the liquid surface, the low-pressure air in the pressurization chamber passes through the filter cake and flows out from the filter disc. This process can dry the filter cake, but it also leads to the loss of low-pressure air. Since increasing the filtration pressure within a certain range increases the thickness of the filter cake adhering to the filter disc, and the increase in filter cake thickness increases the resistance of low-pressure air passing through the filter cake in the pressurization chamber, it reduces the loss rate of low-pressure air and also reduces the low-pressure air volume required to dry a unit mass of output.

[0033] Based on the above research findings, in this embodiment, step S4 includes: increasing the intake air volume of low-pressure air in the pressurization chamber until the filtration pressure is increased to a specified pressure; then controlling the intake air volume of low-pressure air to a value that is dynamically equal to the consumption of low-pressure air, so that the filtration pressure is maintained at the specified pressure.

[0034] During the discharge process following step S4, the thickness of the newly formed filter cake increases accordingly due to the increased filtration pressure. After a certain period (i.e., after the newly formed filter cake adheres to the filter disc above the liquid surface), the loss (i.e., consumption) of low-pressure air decreases due to the obstruction of the newly formed filter cake. The intake volume of low-pressure air during the discharge process needs to be controlled to dynamically equal its loss volume to maintain the filtration pressure at a specified level. Therefore, by detecting the intake volume of low-pressure air, the consumption of low-pressure air within a certain number of discharge cycles can be determined. As can be seen from the above, increasing the filtration pressure can reduce the consumption of low-pressure air, thereby reducing energy consumption.

[0035] In this embodiment, each discharge group includes multiple discharges; the moisture content of the produced material is the average moisture content of the produced material from multiple discharges; the energy consumption is the energy consumed per unit mass of produced material, for example, the energy consumption is the low-pressure air volume consumed per kilogram of produced material.

[0036] Furthermore, in step S2, before the step of controlling the pressure filtration system to perform a set of discharges according to the current operating parameters, the method further includes: controlling the pressure filtration system to perform a pre-discharge according to the current operating parameters to confirm that the system is in a stable operating state.

[0037] Similarly, in step S5, before the step of controlling the pressure filtration system to perform a set of discharges according to the current operating parameters, the method further includes: controlling the pressure filtration system to perform a pre-discharge according to the current operating parameters to confirm that the system is in a stable operating state.

[0038] Reference Figure 2 Furthermore, step S3 also includes: if the moisture content of the product is less than a set range, then proceed to step S7; if the moisture content of the product is greater than a set range, then proceed to step S8. Reference Figure 3 Step S7 includes: Get the feed concentration under the current operating parameters; Determine whether the feed concentration is less than the set upper limit; if so, increase the feed concentration to the specified concentration; if not, decrease the filtration pressure to the specified pressure. Then return to step S2; Step S8 includes: Get the feed concentration under the current operating parameters; Determine whether the feed concentration is greater than the set lower limit; if yes, reduce the feed concentration to the specified concentration; if no, increase the filtration pressure to the specified pressure. Then return to step S2.

[0039] The applicant's research also found that feed concentration has a certain impact on the system's energy consumption, feed moisture content, and yield. Specifically, increasing the feed concentration will increase the feed moisture content, significantly reduce energy consumption, and significantly increase yield within a certain range. In addition, after the filtration pressure is increased to a certain level, further increases in filtration pressure have little impact on the system's energy consumption, feed moisture content, and yield.

[0040] Based on the above research findings, the method provided by this invention correlates the product moisture content, energy consumption, filtration pressure, and feed concentration, so that each parameter is in a better state of dynamic equilibrium.

[0041] Specifically, when the moisture content of the yield is outside the set range, the following adjustment methods are included: When the moisture content of the product exceeds the upper limit of the set moisture value and the feed concentration exceeds the lower limit of the set concentration value, reduce the feed concentration until the moisture content of the product is within the set range. When the moisture content of the product exceeds the upper limit of the set moisture content and the feed concentration is less than or equal to the lower limit of the set concentration, the feed concentration cannot be reduced further. At this time, the filtration pressure is increased until the moisture content of the product is within the set range. When the moisture content of the product is less than the set lower limit and the feed concentration is less than the set upper limit, increase the feed concentration until the moisture content of the product is within the set range. When the moisture content of the product is less than the set lower limit and the feed concentration is greater than or equal to the set upper limit, the feed concentration cannot be increased. In this case, reduce the filtration pressure to keep the moisture content of the product within the set range.

[0042] By adjusting the above methods, the moisture content of the feed is adjusted to the set range, so that the moisture content, output, energy consumption and feed concentration of the feed are in a better dynamic balance.

[0043] Continue to refer to Figure 2 Step S6 further includes: if the energy consumption change is greater than a set value and the energy consumption increases, then proceed to step S9; Step S9 includes: reducing the filtration pressure to a specified pressure, and then returning to step S2.

[0044] Using the method provided in this embodiment, when the energy consumption value increases by more than a set value, the filtration pressure is reduced and the material is discharged again to prevent the system from operating under overload.

[0045] Furthermore, step S6 also includes: If the moisture content of the product is less than the set range, proceed to step S7; If the moisture content of the product is greater than the set range, proceed to step S8.

[0046] Reference Figure 2 and Figure 3 The control method for the pressurized filtration system provided in this embodiment includes the following steps: S1: System power-on warm-up; S2: Control the pressure filtration system to perform a pre-discharge according to the current operating parameters to confirm that the system is in a stable operating state; Next, the pressure filtration system is controlled to perform a set of discharges according to the current operating parameters; Obtain the moisture content of the feed under the current operating parameters, wherein the moisture content of the feed is the average moisture content of the feed discharged in this group; S3: Determine whether the moisture content of the product is within the set range; If so, proceed to step S4; If the moisture content of the product is less than the set range, proceed to step S7; If the moisture content of the product is greater than the set range, proceed to step S8; S4: Increase the intake air volume of low-pressure air in the pressurization chamber until the filtration pressure in the pressurization chamber is increased to the specified pressure; then control the intake air volume of low-pressure air to be dynamically equal to the consumption of low-pressure air, so that the filtration pressure is maintained at the specified pressure. S5: Control the pressure filtration system to perform a pre-discharge according to the current operating parameters to confirm that the system is in a stable operating state; Next, the pressure filtration system is controlled to perform a set of discharges according to the current operating parameters; The energy consumption change range is obtained. The energy consumption change range is the absolute value of the difference between the energy consumption value of the current group of material discharge and the energy consumption value of the previous group of material discharge. The energy consumption value of each group of material discharge is the low-pressure air volume consumed per unit mass of material produced. Get the product moisture content under the current operating parameters; S6: Determine whether the energy consumption change is less than a set value; If the change in energy consumption is less than a set value, then it is determined whether the moisture content of the product is within a set range. If the change in energy consumption is greater than the set value and the energy consumption decreases, then return to step S3; If the change in energy consumption is greater than the set value and the energy consumption increases, then proceed to step S9; If the moisture content of the product is within the set range, then return to step S5; If the moisture content of the product is less than the set range, proceed to step S7; If the moisture content of the product is greater than the set range, proceed to step S8; S7: Get the feed concentration under the current operating parameters; Determine whether the feed concentration is less than the set upper limit; if so, increase the feed concentration to the specified concentration; if not, decrease the filtration pressure to the specified pressure. Then return to step S2; S8: Get the feed concentration under the current operating parameters; Determine whether the feed concentration is greater than the set lower limit; if yes, reduce the feed concentration to the specified concentration; if no, increase the filtration pressure to the specified pressure. Then return to step S2; S9: Reduce the filtration pressure to the specified pressure, then return to step S2.

[0047] It should be noted that during the material discharge process, low-pressure air needs to be continuously input into the low-pressure chamber to replenish the low-pressure air consumed by the drying filter cake and keep the filtration pressure at the specified pressure.

[0048] In this embodiment, the set amplitude value is specifically 5%. During system operation, if the energy consumption change amplitude is less than 5% and the product moisture value is within the set range, the current filtration pressure is maintained, and the product moisture value and energy consumption change amplitude are continuously monitored and dynamically adjusted in real time; if the energy consumption value decreases and the energy consumption change amplitude is greater than 5%, and the product moisture value is within the set range, the filtration pressure is further reduced; if the energy consumption value increases and the energy consumption change amplitude is greater than 5%, the filtration pressure is reduced twice and the process returns to step S2 to prevent the system from overloading.

[0049] It should be noted that in step S6, the two steps of determining whether the energy consumption change is less than the set value and determining whether the moisture content of the product is within the set range can be performed in any order or simultaneously.

[0050] In summary, the control method of the pressurized filtration system provided in this application combines parameters such as filtration pressure, product moisture content, low-pressure air consumption, and feed concentration to dynamically regulate the system. This enables autonomous judgment and automatic adjustment of various parameters, achieving the goals of energy saving, increased output, and proactive regulation of product moisture content, ensuring that the system is always in an optimal and energy-efficient state during operation.

[0051] The present invention also provides a pressure filtration system, as described above. Figure 4 The system includes a pressure filter 1, a blower 2, a gas flow meter 3, a moisture meter 4, and a control center module 5, wherein: A pressure regulating valve 11 is installed at the low-pressure air inlet of the pressurization chamber of the pressure filter 1, and the blower 2 is connected to the low-pressure air inlet through a pipeline; a gas flow meter 3 is installed on the pipeline between the pressure filter 1 and the blower 2; a moisture meter 4 is used to detect the moisture value of the product; the pressure regulating valve 11, the gas flow meter 3 and the moisture meter 4 are all electrically connected to the control center module 5.

[0052] The working principles of the above components are as follows: The pressure regulating valve 11 can control the low-pressure air intake of the pressurization chamber; a pressure sensor linked to the pressure regulating valve 11 is also installed in the pressurization chamber. By controlling the low-pressure air intake of the pressurization chamber, the filtration pressure in the pressurization chamber can be adjusted, thereby realizing the autonomous adjustment of the filtration pressure. The gas flow meter 3 can detect the gas flow in the low-pressure air inlet pipe in real time. By estimating the gas flow consumed by each group of discharges and the discharge frequency, the low-pressure air volume (i.e. energy consumption value) consumed per unit mass of material produced by each group of discharges can be obtained. Moisture meter 4 can be installed at the discharge belt 8 of the product to detect the moisture value of the product; The control center module 5 is essentially a control motherboard. It has a built-in control algorithm and communicates with the PLC host of the pressure filter 1. The PLC is responsible for collecting signals from various parts and sending the signals to the control center module 5. The control center module 5 uses its built-in algorithm to make judgments and sends the results to the PLC. The PLC then issues control commands based on the results from the control center module 5 to control the adjustment of various parameters.

[0053] The pressurized filtration system provided in this application achieves autonomous adjustment of parameters such as product moisture content, filtration pressure, and system energy consumption through the coordinated operation of various components, enabling the pressurized operating conditions to be adjusted to the optimal and most energy-efficient state.

[0054] Optionally, a gas storage tank 9 for storing gas is provided on the pipeline between the blower 2 and the pressure filter 1.

[0055] Continue to refer to Figure 4 The pressure filter 1 is equipped with an upper filtrate valve 12 and a lower filtrate valve 13 at the upper filtrate port and the lower filtrate port, respectively; and / or, the pressure filter 1 is equipped with a level gauge 14.

[0056] In this embodiment, the main shaft of the pressure filter 1 is equipped with a frequency converter. The control center module 5 can control the frequency converter to adjust the main shaft speed, thereby achieving automatic adjustment of the main shaft speed. An upper filtrate valve 12 and a lower filtrate valve 13 are respectively installed at the upper and lower filtrate inlets of the pressure filter 1. Both the upper and lower filtrate valves 12 and 13 are electrically adjustable pressure valves. By controlling the opening degree of the upper and lower filtrate valves 12 and 13, the filtrate and the flowing gas can be controlled, thereby more accurately adjusting the output, moisture content, and energy consumption. The pressure filter 1 is also equipped with a level gauge 14 for detecting the material level. The output can be determined by the detection result of the level gauge 14.

[0057] Furthermore, the pressure filtration system also includes a feed tank 6 for storing the solid-liquid mixture to be filtered; the feed tank 6 is connected to the pressure filter 1 via a pipeline, and a feed pump 63 is installed on the pipeline between the feed tank 6 and the pressure filter 1; a concentration meter 61 and / or a level gauge 62 are installed on the feed tank 6.

[0058] In this embodiment, a concentration meter 61 for detecting the feed concentration is installed in the feed tank 6. The control center module 5 can control parameters such as concentration time according to the detection results of the concentration meter 61 to adjust the feed concentration to the optimal level. A level meter 62 for detecting the liquid level is also installed in the feed tank 6. The control center module 5 can adjust the production rate according to the detection results of the level meter 62. When the liquid level in the feed tank 6 is insufficient, the feed pump 63 is stopped, thereby ensuring the normal operation of the system.

[0059] Furthermore, the pressurized filtration system also includes a deep cone thickener 7, the bottom of which is connected to the feed tank 6 via an underflow pump 71; the underflow pump 71 is connected to a frequency converter 72.

[0060] In this embodiment, the underflow pump 71 of the deep cone thickener 7 is equipped with a frequency converter 72. The control center module 5 can control the frequency converter 72 to adjust the speed of the underflow pump 71, thereby controlling the concentration time and achieving the purpose of adjusting the feed concentration. The feed tank 6 is connected between the pressure filter 1 and the deep cone thickener 7, and it serves to temporarily store the solid-liquid mixture to be filtered, facilitating the detection and control of the feed concentration.

[0061] The working principle of the pressure filtration system is as follows: Parameter detection principle: During system operation, the moisture content of the output material is detected in real time by the moisture meter 4, the gas flow rate in the low-pressure air inlet pipe is detected in real time by the gas flow meter 3, and the feed concentration is detected in real time by the concentration meter 61. Data processing principle: The control center module 5 can calculate the average output moisture value of each group of discharges based on the data measured by the moisture meter 4, calculate the energy consumption change of adjacent two groups of discharges based on the data measured by the gas flow meter 3 and the output of each group of discharges, and obtain the feed concentration under the current state based on the data measured by the concentration meter 61. Control principle: The control center module 5 can adjust the opening of the pressure regulating valve 11 and the speed of the underflow pump 71 according to the average output moisture value, energy consumption variation and feed concentration, thereby adjusting the filtration pressure and feed concentration, so that the parameters such as filtration pressure, output moisture value, energy consumption value and feed concentration are in a dynamic balance state.

[0062] In summary, the pressure filtration system provided in this embodiment can autonomously adjust parameters such as product moisture content, feed concentration, filtration pressure, system energy consumption, and filtrate valve opening, thereby ensuring that the pressure filter 1 operates under optimal parameters, avoiding energy waste, ensuring product quality, and increasing output.

[0063] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A control method for a pressurized filtration system, characterized in that, Includes the following steps: S2: Control the pressure filtration system to perform a set of discharges according to the current operating parameters; Get the product moisture content under the current operating parameters; S3: Determine whether the moisture content of the product is within the set range; If so, proceed to step S4; S4: Increase the filtration pressure to the specified pressure; S5: Control the pressure filtration system to perform a set of discharges according to the current operating parameters; Obtain the energy consumption change rate, which is the absolute value of the difference between the energy consumption value of the current set of material discharges and the energy consumption value of the previous set of material discharges; obtain the product moisture value under the current operating parameters; The energy consumption value is the amount of low-pressure air consumed; S6: Determine whether the energy consumption change is less than a set value; If so, return to step S5; If the change in energy consumption is greater than the set value and the energy consumption decreases, then return to step S3.

2. The control method for the pressurized filtration system according to claim 1, characterized in that, Step S3 further includes: if the moisture content of the product is less than a set range, then proceed to step S7; Step S7 includes: Get the feed concentration under the current operating parameters; Determine whether the feed concentration is less than the set upper limit; if so, increase the feed concentration to the specified concentration; if not, decrease the filtration pressure to the specified pressure. Then return to step S2.

3. The control method for the pressurized filtration system according to claim 2, characterized in that, Step S3 further includes: if the moisture content of the product is greater than a set range, then proceed to step S8; Step S8 includes: Get the feed concentration under the current operating parameters; Determine whether the feed concentration is greater than the set lower limit; if yes, reduce the feed concentration to the specified concentration; if no, increase the filtration pressure to the specified pressure. Then return to step S2.

4. The control method for the pressurized filtration system according to claim 3, characterized in that, Step S6 further includes: determining whether the moisture content of the product is within a set range; If the change in energy consumption is less than the set value and the moisture content of the product is within the set range, then return to step S5; If the moisture content of the product is less than the set range, proceed to step S7; If the moisture content of the product is greater than the set range, proceed to step S8.

5. The control method for the pressurized filtration system according to claim 1, characterized in that, Step S6 further includes: if the energy consumption change is greater than a set value and the energy consumption increases, then proceed to step S9; Step S9 includes: reducing the filtration pressure to a specified pressure, and then returning to step S2.

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