Pressure filtration method, pressure filtration machine, electronic device, and medium

Abstract

The application provides a kind of pressurized filtration method, pressurized filtration machine, electronic equipment and medium, comprising: material is sent into filtration zone, according to first preset pressure value to filtration zone pressurization, to make material solid-liquid separation and obtain first filter cake;First filter cake is sent into gas drainage zone, obtains the first parameter information of first filter cake, and determines the pressure value and action time of gas drainage zone based on the first parameter information of first filter cake, and based on the pressure value and action time of gas drainage zone control compressed air enters gas drainage zone and obtains second filter cake;Second filter cake is sent into through-flow zone, obtains the second parameter information of second filter cake, and determines the pressure value and action time of through-flow zone based on the second parameter information of second filter cake, and based on the pressure value and action time of through-flow zone control compressed air enters through-flow zone and obtains third filter cake;Third filter cake is sent into unloading zone and obtains final filter cake, and final filter cake is discharged.The application reduces filter cake moisture content and unit energy consumption.

Description

Technical Field

[0001] This invention relates to the field of pressure filtration technology, and in particular to a pressure filtration method, a pressure filter, an electronic device, and a medium. Background Technology

[0002] Pressure filters are core equipment for dewatering flotation clean coal and phosphate tailings in coking coal preparation plants. However, they suffer from problems such as a single filtration principle and inability to adjust pressure, which can lead to high moisture content in flotation clean coal and phosphate ore, as well as high energy consumption per unit processing capacity. Summary of the Invention

[0003] In view of this, the purpose of the present invention is to provide a pressure filtration method, a pressure filter, an electronic device and a medium to reduce the moisture content of the filter cake and the unit energy consumption.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0005] In a first aspect, the present invention provides a pressure filtration method applied to a filtration device of a pressure filter, the filtration device comprising: a filtration zone, an air-to-water drainage zone, a flow-through zone, and a discharge zone; the method comprising: feeding material into the filtration zone, pressurizing the filtration zone according to a first preset pressure value to achieve solid-liquid separation of the material to obtain a first filter cake; feeding the first filter cake into the air-to-water drainage zone, acquiring first parameter information of the first filter cake, determining the pressure value and action time of the air-to-water drainage zone based on the first parameter information of the first filter cake, and controlling compressed air to enter the air outlet based on the pressure value and action time of the air-to-water drainage zone. In the water zone, compressed air is introduced into the first filter cake to remove moisture and obtain the second filter cake. The second filter cake is then sent into the flow-through zone, where second parameter information of the second filter cake is obtained. Based on the second parameter information, the pressure value and action time of the flow-through zone are determined, and compressed air is controlled to enter the flow-through zone based on the pressure value and action time of the flow-through zone, so that the compressed air flows through the second filter cake to remove moisture and obtain the third filter cake. The third filter cake is then sent into the discharge zone, where it is pressurized according to a second preset pressure value to obtain the final filter cake, and the final filter cake is discharged. The second preset pressure value is negative pressure.

[0006] Optionally, the first parameter information includes at least: the thickness of the first filter cake, the surface tension coefficient, the capillary radius, and the contact angle; determining the pressure value and action time of the air-drainage zone based on the first parameter information of the first filter cake includes: determining the pressure value of the air-drainage zone according to preset air-drainage conditions based on the first parameter information of the first filter cake; wherein, the air-drainage conditions include: ΔP2>2L1a1cosθ1 / πr1 3ΔP2 represents the pressure value of the air-drainage zone, L1 represents the thickness of the first filter cake, a1 represents the surface tension coefficient of the first filter cake, θ1 represents the contact angle, and r1 represents the capillary radius of the first filter cake. Based on the pressure value of the air-drainage zone, the first air volume flow rate of compressed air passing through the capillaries of the first filter cake is calculated according to Poiseuille's law. The duration of action of the compressed air in the air-drainage zone is obtained by integrating the first air volume flow rate.

[0007] Optionally, controlling the entry of compressed air into the air-drainage zone based on the pressure value and action time of the air-drainage zone includes: generating a first control signal based on the pressure value and action time of the air-drainage zone, and controlling the air volume and air outlet time of the air-drainage zone based on the first control signal.

[0008] Optionally, the second parameter information includes at least: the thickness of the second filter cake, surface tension coefficient, capillary radius, contact angle, filter cake permeability, cross-sectional area, density, diameter, number, and total mass of solid particles in the second filter cake, and the thickness of the water film adhering to the surface of the second filter cake.

[0009] Optionally, determining the pressure value and duration of the flow-through zone based on the second parameter information of the second filter cake includes: determining the pressure value of the flow-through zone according to preset flow-through conditions based on the second parameter information of the second filter cake; wherein, the flow-through conditions include: ΔP3=fL2ρQ 2 / 4π 2 r2 5 And ΔP3>2L2a2cosθ2 / πr2 3 ΔP3 represents the pressure value of the air-to-water drainage zone, L2 represents the thickness of the second filter cake, f represents the air friction resistance coefficient, ρ represents the compressed air density, Q represents the capillary airflow of the second filter cake, a2 represents the surface tension coefficient of the second filter cake, θ2 represents the contact angle, and r2 represents the capillary radius of the second filter cake. Based on the pressure value of the flow-through zone and the filter cake permeability of the second filter cake, the second air volume flow rate of the compressed air passing through the second filter cake is calculated according to Darcy's law. Based on the density, diameter, and number of solid particles in the second filter cake, the total specific surface area of ​​the solid particles in the second filter cake is calculated, and based on the total specific surface area, total mass, and water film thickness of the solid particles in the second filter cake, the volume of water adhering to the surface of the second filter cake is calculated. Based on the volume of water adhering to the surface of the second filter cake and the second air volume flow rate, the action time of the compressed air in the flow-through zone is obtained by integrating.

[0010] Optionally, after calculating the second air volume flow rate of the compressed air passing through the second filter cake according to Darcy's law, the method further includes: correcting the second air volume flow rate based on the evaporation rate of the water adhering to the surface of the second filter cake to obtain the corrected air volume flow rate.

[0011] Optionally, controlling the entry of compressed air into the cross-flow zone based on the pressure value and action time of the cross-flow zone includes: generating a second control signal based on the pressure value and action time of the cross-flow zone, and controlling the air volume and air outlet time of the cross-flow zone based on the second control signal.

[0012] In a second aspect, the present invention provides a pressure filter, comprising: a filter device, the filter device comprising: a filter zone, an air-to-water zone, a flow-through zone and a discharge zone; the filter device performs filtration using any of the pressure filtration methods provided in the first aspect above.

[0013] Thirdly, the present invention provides an electronic device including a processor and a memory, the memory storing computer-executable instructions executable by the processor, the processor executing the computer-executable instructions to implement the steps of the method provided in any of the first aspects above.

[0014] Fourthly, the present invention provides a computer-readable storage medium storing a computer program, wherein the computer program, when executed by a processor, performs the steps of the method provided in any of the first aspects above.

[0015] This invention brings the following beneficial effects:

[0016] The pressure filtration method, pressure filter, electronic device, and medium provided by this invention are applied to the filtration device of a pressure filter. The filtration device includes a filtration zone, an air-to-water drainage zone, a flow-through zone, and a discharge zone. First, material is fed into the filtration zone, and pressure is applied to the filtration zone according to a first preset pressure value to achieve solid-liquid separation of the material and obtain a first filter cake. Then, the first filter cake is fed into the air-to-water drainage zone, and first parameter information of the first filter cake is obtained. Based on the first parameter information of the first filter cake, the pressure value and action time of the air-to-water drainage zone are determined, and compressed air is controlled to enter based on the pressure value and action time of the air-to-water drainage zone. The process involves three filter cakes: a first filter cake (air-drainage zone) and a second filter cake (compressed air entering the first filter cake to remove moisture). The second filter cake is then fed into a flow-through zone where second parameter information is obtained. Based on this information, the pressure and duration of the flow-through zone are determined, and compressed air is controlled to flow through the second filter cake, carrying away moisture and forming a third filter cake. Finally, the third filter cake is fed into a discharge zone where a second preset pressure is applied to obtain the final filter cake, which is then discharged. The second preset pressure is negative. This method sequentially passes the material through the filtration zone, air-drainage zone, and flow-through zone for dehydration and filtration, using different pressures and durations in each zone. This achieves efficient dehydration, reducing the moisture content of the filter cake and lowering energy consumption per unit area.

[0017] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention.

[0018] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0019] 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.

[0020] Figure 1 This is a schematic diagram of the area division of a pressure filter device provided in an embodiment of the present invention;

[0021] Figure 2 A schematic diagram of a permeable sand bed model provided in an embodiment of the present invention;

[0022] Figure 3 A schematic diagram of air drainage provided in an embodiment of the present invention;

[0023] Figure 4 A schematic diagram of flow through the air provided in an embodiment of the present invention;

[0024] Figure 5 A flowchart of a pressurized filtration method provided in an embodiment of the present invention;

[0025] Figure 6 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, 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.

[0027] Currently, pressure filters suffer from problems such as a single filtration principle and inability to adjust pressure, which can lead to high moisture content in flotation clean coal and high energy consumption per unit processing capacity.

[0028] Based on this, the pressure filtration method, pressure filter, electronic equipment and medium provided in the embodiments of the present invention can reduce the moisture content of the filter cake and the unit energy consumption.

[0029] To facilitate understanding of this embodiment, a pressure filtration method disclosed in this invention will first be described in detail. This method is applied to the filtration device of a pressure filter. See [link to relevant documentation]. Figure 1 The diagram shows the area division of a pressure filter device, which includes: a filtration zone 1, an air-to-water drainage zone 2, a flow-through zone 3, and a discharge zone 4.

[0030] Filtration zone 1 is mainly for solid-liquid separation. The filtrate (i.e., the material) passes through the filter cloth, and the solids accumulate on the filter cloth to form a filter cake of a certain thickness. At this time, the filter cake has a high water content, and most of the water is stored in the capillary structure of the filter cake. By increasing the pressure value ΔP1 of filtration zone 1, the thickness of the filter cake can be greatly increased, thereby increasing the processing capacity of the equipment.

[0031] See Figure 2 The diagram shows a permeable sand bed model. This model assumes the filter cake structure is similar to that of a sand layer, a disordered porous particle bed structure, except the filter cake is thinner and the solid particles are finer. The filtration process follows Darcy's equation, where the rate at which the liquid passes through the capillary is inversely proportional to the viscosity of the liquid, i.e.:

[0032]

[0033] Where ΔP is the pressure difference across the filter cake, L is the filter cake thickness, Q is the volumetric flow rate, A is the filter cake cross-sectional area, μ is the fluid viscosity, and k is the permeability coefficient.

[0034] In the filtration process, the best way to increase the filtration speed (increase the flow rate Q) is to increase the pressure difference ΔP and reduce the material thickness. K in this formula is the permeability coefficient, which is directly related to the particle size distribution, wetting angle, van der Waals force, and viscosity of the material. If the filter aid is added to change the charge or wettability, the filtration effect will be increased.

[0035] In the air-drainage zone 2, compressed air enters the filter cake and displaces most of the liquid water in the capillary structure, reducing the moisture content of the filter cake. A large amount of water is discharged in this stage, and the remaining water is coated on the surface of the solid particles due to surface tension. The pressure value ΔP2 in the air-drainage zone 2 needs to meet the requirements of capillary drainage formed by the relatively large thickness of the filter cake in the filtration stage. The action time in this stage is relatively short, so the fan-shaped area is less than or equal to 30°.

[0036] See Figure 3The diagram illustrates an air-to-water drainage method. On both sides of the filter cake, a pressure difference ΔP2 is created between the high-pressure zone (formed by high-pressure air) and the low-pressure zone. According to the capillary resistance formula, the basic condition for air-to-water drainage in a horizontal capillary is: ΔP2 > 2Lacosθ / πr 3 Here, ΔP2 must be sufficient to meet the pressure requirements for air drainage in order to open the capillary tube and drain the water inside, thus opening the capillary tube structure.

[0037] In the through-flow zone 3, compressed air flows through the filter cake to remove moisture from the surface of solid particles. This zone is characterized by a long time required, but the required pressure difference ΔP3 is relatively small. Therefore, this zone is greater than or equal to 45°. If the pressure difference is large, the energy consumption will increase significantly.

[0038] See Figure 4 The diagram shows a flow pattern. After the air-water drainage process is completed, some small water droplets will remain in the capillary. This water will be carried away by the air. Since the capillary has been opened, the required pressure difference ΔP3 is relatively small.

[0039] ΔP3 should follow the basic fluid equation: ΔP3=kQ 2 k is a function of capillary radius r and filter cake thickness L: k = fLρ / 4π 2 r 5 .

[0040] The formula is transformed to obtain: ΔP3>2Lacosθ / πr 3 Meanwhile, ΔP3=fLρQ 2 / 4π 2 r 5 .

[0041] In the formula, ΔP3 is the pressure difference, a is the surface tension coefficient, Q is the volumetric flow rate of each capillary, θ is the contact angle, r is the capillary radius, L is the filter cake thickness, f is the air friction resistance coefficient, and ρ is the compressed air density.

[0042] The unloading zone 4 functions similarly to the existing pressure filter. ΔP4 is a positive pressure, which needs to be greater than the pressure inside the pressure filter tank. The specific value can be set according to the actual production conditions. At the same time, a transition zone is set between the air drainage zone 2, the flow zone 3, and the unloading zone 4. The transition zone can be adjusted according to the air discharged by the air drainage, the air discharged by the blower drainage, and the moisture content of the coal slime products.

[0043] Based on the above-mentioned filtration device, see Figure 5 The flowchart shown illustrates a pressurized filtration method, which mainly includes the following steps S501 to S504:

[0044] Step S501: The material is fed into the filtration zone and pressurized according to the first preset pressure value to separate the solid and liquid components of the material to obtain the first filter cake.

[0045] In one embodiment, the material can be peat. After the peat enters the filtration zone, it is pressurized according to a first preset pressure value to allow the filtrate to pass through the filter cloth, and the solids accumulate on the filter cloth to form a first filter cake of a certain thickness. The first preset pressure value ΔP1 can be set according to the actual production situation, but ΔP1 needs to be above 0.65 MPa.

[0046] Step S502: Send the first filter cake into the air-drainage zone, obtain the first parameter information of the first filter cake, and determine the pressure value and action time of the air-drainage zone based on the first parameter information of the first filter cake. Also, control the compressed air to enter the air-drainage zone based on the pressure value and action time of the air-drainage zone, so that the compressed air enters the first filter cake to remove moisture and obtain the second filter cake.

[0047] In one embodiment, after the first filter cake generated in the filtration zone enters the air-drainage zone, first parameter information of the first filter cake is acquired. The first parameter information includes at least: the thickness of the first filter cake, the surface tension coefficient, the capillary radius, and the contact angle. Then, based on the first parameter information, the required pressure value and action time for the air-drainage zone are calculated. Compressed air is then controlled to enter the air-drainage zone according to the pressure value and action time of the air-drainage zone, so that the compressed air enters the first filter cake, displacing most of the liquid water in the capillary, thus obtaining the second filter cake.

[0048] Step S503: Send the second filter cake into the flow-through zone, obtain the second parameter information of the second filter cake, and determine the pressure value and action time of the flow-through zone based on the second parameter information of the second filter cake. Also, control the compressed air to enter the flow-through zone based on the pressure value and action time of the flow-through zone, so that the compressed air flows through the second filter cake to remove moisture and obtain the third filter cake.

[0049] In one embodiment, after the second filter cake obtained in the air-drainage zone enters the flow-through zone, the second parameter information of the second filter cake is obtained. The second parameter information includes at least: the thickness of the second filter cake, the surface tension coefficient, the capillary radius, the contact angle, the filter cake permeability, the cross-sectional area, the density, diameter, number, and total mass of the solid particles in the second filter cake, and the thickness of the water film attached to the surface of the second filter cake.

[0050] Then, the required pressure and action time of the flow-through zone are calculated based on the second parameter information. Compressed air is then controlled to enter the flow-through zone based on the pressure and action time of the flow-through zone, so that the compressed air flows through the second filter cake and removes the moisture on the surface of the solid particles to obtain the third filter cake.

[0051] Step S504: The third filter cake is fed into the unloading area, and the unloading area is pressurized according to the second preset pressure value to obtain the final filter cake, and the final filter cake is discharged.

[0052] In one embodiment, the third filter cake obtained in the flow-through zone enters the discharge zone, where a second preset pressure value is applied according to a negative pressure. This second preset pressure value can be set according to actual production conditions. After pressurized filtration in the discharge zone, the final filter cake is obtained and discharged from the equipment.

[0053] The pressure filtration method provided by the present invention sequentially passes the material through a filtration zone, an air-to-water drainage zone, and a flow-through zone for dehydration and filtration, and uses different pressure values ​​and action times in different zones, thereby achieving efficient dehydration, reducing the moisture content of the filter cake and the unit energy consumption.

[0054] In one embodiment, for the aforementioned step S502, i.e., when determining the pressure value and action time of the air-drainage zone based on the first parameter information of the first filter cake, and controlling the entry of compressed air into the air-drainage zone based on the pressure value and action time of the air-drainage zone, the following methods may be adopted, including but not limited to:

[0055] First, based on the first parameter information of the first filter cake, the pressure value of the air drainage zone is determined according to the preset air drainage conditions.

[0056] Among them, the air drainage conditions include: ΔP2>2L1a1cosθ1 / πr1 3 ΔP2 represents the pressure value of the air-drainage zone, L1 represents the thickness of the first filter cake, a1 represents the surface tension coefficient of the first filter cake, θ1 represents the contact angle, and r1 represents the capillary radius of the first filter cake. In specific implementation, the final pressure value of the air-drainage zone is determined based on the critical value calculated above and in combination with the actual production conditions.

[0057] Secondly, based on the pressure value of the air-drainage zone, the first air volume flow rate of compressed air passing through the capillary of the first filter cake is calculated according to Poiseuille's law.

[0058] In practical implementation, the gas-water discharge process can be approximated as viscous flow of fluid in capillaries. This process has an extremely low Reynolds number, and the viscous flow can be considered laminar flow, which can be calculated using Poiseuille's law. Specifically, the relationship between the volumetric flow rate Q and the pressure value ΔP is as follows:

[0059]

[0060] In this embodiment, the first air volume flow rate Q1 can be calculated according to the following formula:

[0061]

[0062] Then, the duration of compressed air action in the air-water drainage zone is obtained by integrating the first air volume flow rate.

[0063] In practical implementation, the action time t is the time required for the fluid to pass through the capillary, which can be obtained by integrating the volumetric flow rate:

[0064]

[0065] Where V represents the total volume of fluid flowing through the capillary (unit: m3).

[0066] Substituting Q into the integral:

[0067]

[0068] Assuming ΔP is constant, the integral result is:

[0069]

[0070] The final gas drainage zone action time t is:

[0071]

[0072] Finally, a first control signal is generated based on the pressure value and action time of the gas drainage zone, and the air volume and air duration of the air outlet of the gas drainage zone are controlled based on the first control signal.

[0073] In practical implementation, the air drainage zone is equipped with an air outlet. A first control signal is generated based on the pressure value and action time of the air drainage zone, and the first control signal is sent to the controller of the air outlet of the air drainage zone. The controller controls the air volume and air duration of the air outlet of the air drainage zone according to the first control signal, so that the air drainage zone is maintained at the calculated pressure value and continuous action time.

[0074] In one implementation, for the aforementioned step S503, i.e., when determining the pressure value and action time of the crossflow zone based on the second parameter information of the second filter cake, and controlling the entry of compressed air into the crossflow zone based on the pressure value and action time of the crossflow zone, the following methods may be adopted, including but not limited to:

[0075] First, based on the second parameter information of the second filter cake, the pressure value of the flow-through zone is determined according to the preset flow-through conditions.

[0076] The flow conditions include: ΔP3=fL2ρQ 2 / 4π 2 r2 5 And ΔP3>2L2a2cosθ2 / πr2 3ΔP3 represents the pressure value of the air-to-water drainage zone, L2 represents the thickness of the second filter cake, f represents the air friction coefficient, ρ represents the compressed air density, Q represents the capillary airflow of the second filter cake, a2 represents the surface tension coefficient of the second filter cake, θ2 represents the contact angle, and r2 represents the capillary radius of the second filter cake. In specific implementation, the pressure value ΔP3 of the flow-through zone is calculated according to the above, and it is ensured that ΔP3 > 2L2a2cosθ2 / πr2 3 .

[0077] Secondly, based on the pressure value of the flow-through zone and the filter cake permeability of the second filter cake, the second air volume flow rate of the compressed air passing through the second filter cake is calculated according to Darcy's law.

[0078] In practical implementation, for through-flow, after the air is drained, a certain amount of voids are formed inside the filter cake. The through-flow then carries away the surface moisture of the solid particles in these voids. The flow of fluid in a porous medium can be described by Darcy's law:

[0079]

[0080] Where k represents the filter cake permeability (in %), and A represents the cross-sectional area of ​​the filter cake (in m²). 2 μ represents the dynamic viscosity of air (unit: Pa·s), and L represents the thickness of the filter cake (unit: m).

[0081] The relationship between permeability k and filter cake porosity can be expressed by the Kozeny-Carman equation:

[0082]

[0083] Where C is the Kozeny constant (usually around 5), and S is the specific surface area of ​​the solid particles in the filter cake.

[0084] Assuming that all solid particles are ideally spherical, the specific surface area S of a single particle can be calculated using the following formula:

[0085]

[0086] Where ρ is the density of solid particles in the filter cake (unit: g / m3), i.e., coal particle density; d is the diameter of solid particles in the filter cake (unit: m), i.e., coal particle diameter.

[0087] Assuming there are N solid particles in the filter cake, the total specific surface area of ​​the solid particles in the filter cake is:

[0088]

[0089] The flow rate Q can then be expressed as:

[0090]

[0091] Next, based on the evaporation rate of the water adhering to the surface of the second filter cake, the second air volume flow rate is corrected to obtain the corrected air volume flow rate.

[0092] In practical implementation, according to the two-mode theory, water adhering to the pores diffuses in a molecular manner through a gas film, and its evaporation rate can be expressed as:

[0093]

[0094] in, K is the evaporation rate (kg / s), and kv is the mass transfer coefficient (kg / (m³)). 2 s-kPa), Av is the volatile surface area (m²) 2 Psat is the saturated vapor pressure of water (kPa), and Penv is the partial pressure of water vapor in the environment (kPa).

[0095] The evaporation process reduces the mass of water in the pores, thus affecting the flow process. Assuming the evaporated water is carried away by the airflow, the evaporation rate can be... Converted to volume change rate Therefore, the Darcy's law formula is modified as follows:

[0096]

[0097] Where ρw is the density of water (unit: kg / m3).

[0098] The corrected volumetric flow rate is then obtained:

[0099]

[0100] Then, the total specific surface area of ​​the solid particles in the second filter cake is calculated based on the density, diameter and number of solid particles in the second filter cake, and the volume of water adhering to the surface of the second filter cake is calculated based on the total specific surface area, total mass and water film thickness of the solid particles in the second filter cake.

[0101] Subsequently, the duration of compressed air action in the flow-through zone is calculated by integrating the volume of water adhering to the surface of the second filter cake with the volumetric flow rate of the second air.

[0102] In practical implementation, the volume of water adhering to the surface of coal particles can be approximately calculated using the following formula:

[0103] V_attached water = S × A × δ

[0104] Where S is the total specific surface area of ​​solid particles in the filter cake (unit: m2 / g), which can be calculated based on the aforementioned formula combined with the density, diameter and number of solid particles; A is the total mass of solid particles (unit: g); δ is the thickness of the water film attached to the particle surface (m).

[0105] The final volatilization time t (i.e., the duration of action) can be solved by volume integration:

[0106]

[0107] Q 修正 Substitute the expression:

[0108]

[0109] Assume Q. If the flow process remains constant, it can be simplified as follows:

[0110]

[0111] In summary, the formula for the final duration t of the flow-through region is:

[0112]

[0113] Finally, a second control signal is generated based on the pressure value and duration of the flow-through zone, and the air volume and duration of the air outlet in the flow-through zone are controlled based on the second control signal.

[0114] In practical implementation, the flow-through zone is equipped with an air outlet. A second control signal is generated based on the pressure value and duration of the flow-through zone and sent to the controller at the air outlet of the flow-through zone. The controller controls the air volume and duration of the air outlet of the flow-through zone according to the second control signal, thereby maintaining the flow-through zone at the calculated pressure value and duration of the continuous action.

[0115] The method provided in this embodiment of the invention employs three methods in sequence: filtration, air drainage, and air flow. The filtration device of the pressure filter is divided into zones, and a resistance valve is installed at the air outlet to achieve different pressure differences in different zones. This enables the filtration, air drainage, and air flow processes to be completed, thereby increasing the amount of coal slime processed and reducing the moisture content of the filter cake and the unit energy consumption.

[0116] This invention also provides a pressure filter, comprising: a filter device, the filter device including: a filter zone, an air-to-water zone, a flow-through zone and a discharge zone; the filter device performs filtration using any of the pressure filtration methods provided in the foregoing embodiments.

[0117] The pressure filter provided by the present invention sequentially passes the material through a filtration zone, an air-drainage zone, and a flow-through zone for dehydration and filtration, and uses different pressure values ​​and action times in different zones, thereby achieving efficient dehydration, reducing the moisture content of the filter cake and the unit energy consumption.

[0118] It should be noted that the pressure filter provided in this embodiment of the invention has the same implementation principle and technical effects as the aforementioned method embodiment. For the sake of brevity, any parts not mentioned in the pressure filter embodiment can be referred to the corresponding content in the aforementioned method embodiment. The specific numerical values ​​provided in this embodiment are merely exemplary and are not intended to limit the scope of the invention.

[0119] This invention also provides an electronic device, specifically, the electronic device includes a processor and a storage device; the storage device stores a computer program, and the computer program, when run by the processor, executes the method described in any of the above embodiments.

[0120] Figure 6 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention. The electronic device 100 includes: a processor 60, a memory 61, a bus 62, and a communication interface 63. The processor 60, the communication interface 63, and the memory 61 are connected through the bus 62. The processor 60 is used to execute executable modules, such as computer programs, stored in the memory 61.

[0121] The memory 61 may include high-speed random access memory (RAM) or non-volatile memory, such as at least one disk storage device. Communication between this system network element and at least one other network element is achieved through at least one communication interface 63 (which can be wired or wireless), such as the Internet, wide area network, local area network, metropolitan area network, etc.

[0122] Bus 62 can be an ISA bus, PCI bus, or EISA bus, etc. The bus can be divided into address bus, data bus, control bus, etc. For ease of representation, Figure 6 The symbol is represented by a single double-headed arrow, but this does not mean that there is only one bus or one type of bus.

[0123] The memory 61 is used to store programs. After receiving an execution instruction, the processor 60 executes the program. The method executed by the device for defining the flow process disclosed in any of the foregoing embodiments of the present invention can be applied to the processor 60 or implemented by the processor 60.

[0124] Processor 60 may be an integrated circuit chip with signal processing capabilities. In implementation, each step of the above method can be completed by the integrated logic circuitry in the hardware of processor 60 or by instructions in software form. Processor 60 can be a general-purpose processor, including a Central Processing Unit (CPU), a Network Processor (NP), etc.; it can also be a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field-Programmable Gate Array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. It can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of this invention. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the methods disclosed in the embodiments of this invention can be directly embodied in the execution of a hardware decoding processor, or executed by a combination of hardware and software modules in the decoding processor. The software modules can reside in random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, or other mature storage media in the art. The storage medium is located in memory 61. Processor 60 reads the information in memory 61 and, in conjunction with its hardware, completes the steps of the above method.

[0125] The computer program product of the readable storage medium provided in the embodiments of the present invention includes a computer-readable storage medium storing program code. The instructions included in the program code can be used to execute the methods described in the foregoing method embodiments. For specific implementation, please refer to the foregoing method embodiments, which will not be repeated here.

[0126] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, essentially, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0127] Finally, it should be noted that the above-described embodiments are merely specific implementations of the present invention, used to illustrate the technical solutions of the present invention, and not to limit it. The scope of protection of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments within the technical scope disclosed in the present invention, or make equivalent substitutions for some of the technical features; and these modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A pressure filtration method, characterized in that, A filtration device applied to a pressure filter, the filtration device comprising: a filtration zone, an air-to-water zone, a flow-through zone, and a discharge zone; the method comprising: The material is fed into the filtration zone and pressurized according to a first preset pressure value to separate the material into solid and liquid and obtain a first filter cake. The first filter cake is fed into the air-drainage zone, the first parameter information of the first filter cake is obtained, and the pressure value and action time of the air-drainage zone are determined based on the first parameter information of the first filter cake. Compressed air is controlled to enter the air-drainage zone based on the pressure value and action time of the air-drainage zone, so that the compressed air enters the first filter cake to remove moisture and obtain the second filter cake. The second filter cake is fed into the flow-through zone, the second parameter information of the second filter cake is obtained, and the pressure value and action time of the flow-through zone are determined based on the second parameter information of the second filter cake. Compressed air is controlled to enter the flow-through zone based on the pressure value and action time of the flow-through zone, so that the compressed air flows through the second filter cake to remove moisture and obtain the third filter cake. The third filter cake is fed into the unloading zone, and the unloading zone is pressurized according to the second preset pressure value to obtain the final filter cake, and the final filter cake is discharged; wherein, the second preset pressure value is negative pressure; The first parameter information includes at least: the thickness of the first filter cake, the surface tension coefficient, the capillary radius, and the contact angle; Determining the pressure value and action time of the air-drainage zone based on the first parameter information of the first filter cake includes: Based on the first parameter information of the first filter cake, the pressure value of the air drainage zone is determined according to preset air drainage conditions; wherein, the air drainage conditions include: P2>2 L 1 a 1cos θ 1 / π r 1 3 , P2 represents the pressure value of the gas drainage zone. L 1 represents the thickness of the first filter cake. a 1 represents the surface tension coefficient of the first filter cake. θ 1 represents the contact angle. r 1 represents the capillary radius of the first filter cake; Based on the pressure value of the air-drainage zone, the first air volume flow rate of compressed air passing through the capillary tube of the first filter cake is calculated according to Poiseuille's law. The duration of compressed air action in the air-drainage zone is obtained by integrating the first air volume flow rate.

2. The method according to claim 1, characterized in that, Controlling the entry of compressed air into the air-drainage zone based on the pressure value and duration of the air-drainage zone includes: A first control signal is generated based on the pressure value and duration of the air drainage zone, and the air volume and duration of the air outlet of the air drainage zone are controlled based on the first control signal.

3. The method according to claim 1, characterized in that, The second parameter information includes at least: the thickness of the second filter cake, surface tension coefficient, capillary radius, contact angle, filter cake permeability, cross-sectional area, density, diameter, number, and total mass of solid particles in the second filter cake, and the thickness of the water film adhering to the surface of the second filter cake.

4. The method according to claim 3, characterized in that, Determining the pressure value and duration of the flow-through zone based on the second parameter information of the second filter cake includes: Based on the second parameter information of the second filter cake, the pressure value of the flow-through zone is determined according to preset flow-through conditions; wherein, the flow-through conditions include: P3= fL 2 ρQ 2 / 4π 2 r 2 5 and P3>2 L 2 a 2cos θ 2 / π r 2 3 , P3 represents the pressure value in the flow-through region. L 2 represents the thickness of the second filter cake. f Indicates the coefficient of air friction drag. ρ Indicates the density of compressed air. Q This indicates the capillary airflow rate of the second filter cake. a 2 represents the surface tension coefficient of the second filter cake. θ 2 represents the contact angle. r 2 represents the capillary radius of the second filter cake; Based on the pressure value of the flow-through zone and the filter cake permeability of the second filter cake, the second air volume flow rate of the compressed air passing through the second filter cake is calculated according to Darcy's law; The total specific surface area of ​​the solid particles in the second filter cake is calculated based on the density, diameter and number of solid particles in the second filter cake, and the volume of water adhering to the surface of the second filter cake is calculated based on the total specific surface area, total mass and water film thickness of the solid particles in the second filter cake. The duration of compressed air action in the flow zone is calculated by integrating the volume of water adhering to the surface of the second filter cake with the volumetric flow rate of the second air.

5. The method according to claim 4, characterized in that, After calculating the second air volume flow rate of the compressed air passing through the second filter cake according to Darcy's law, the following steps are also included: Based on the evaporation rate of the water adhering to the surface of the second filter cake, the second air volume flow rate is corrected to obtain the corrected air volume flow rate.

6. The method according to claim 4, characterized in that, Controlling the entry of compressed air into the flow-through zone based on the pressure value and duration of the flow-through zone includes: A second control signal is generated based on the pressure value and duration of the flow-through zone, and the air volume and duration of the air outlet in the flow-through zone are controlled based on the second control signal.

7. A pressure filter, characterized in that, include: A filtration device, comprising: a filtration zone, an air-to-water zone, a flow-through zone, and a discharge zone; The filtration device uses the pressure filtration method described in any one of claims 1 to 6 for filtration.

8. An electronic device, characterized in that, The method includes a processor and a memory, the memory storing computer-executable instructions executable by the processor, the processor executing the computer-executable instructions to implement the steps of the method according to any one of claims 1 to 6.

9. A computer-readable storage medium storing a computer program thereon, characterized in that, The computer program is executed by the processor to perform the steps of the method described in any one of claims 1 to 6.

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