Anti-blocking membrane filtering method and anti-blocking membrane filtering system

Abstract

According to the anti-blocking membrane filtration method and the anti-blocking membrane filtration system provided by the embodiment of the invention, the pressure of the filter membrane in the filtration system is obtained, and if the pressure of the filter membrane does not meet the preset pressure condition, the frequency of backflushing the filter membrane is adjusted; the anti-blocking membrane filtering system comprises a filtering device, and the filtering device comprises a to-be-filtered cavity, a filtered cavity and a filtering membrane arranged between the to-be-filtered cavity and the filtered cavity. A first inlet, communicated with the to-be-filtered cavity, on the filtering device is connected to the mortar pipe, a second inlet communicated with the to-be-filtered cavity is connected to the back-flushing pipe, and a first outlet communicated with the filtered cavity is connected to the clear liquid pipe. The method is used for achieving the effect of improving the recoil triggering accuracy.

Description

Technical Field

[0001] The present application relates to the field of membrane filtration, and in particular to an anti-blocking membrane filtration method and an anti-blocking membrane filtration system. Background Art

[0002] When silicon wafers are cut, a large amount of waste liquid is usually generated. In order to save resources, it is particularly important to effectively filter and treat the waste liquid. The membrane technology of the filtration system is the key to treating waste liquid, but the service life of the membrane is limited. Therefore, improving the membrane technology to extend the service life of the filtration system is in great demand in the market.

[0003] In the prior art, during the filtration process, the filter membrane in the filter system is backflushed. Backflushing is to simultaneously send air and backwash water from the bottom of the filter membrane so that the residual substances on the filter membrane are pressured and fall off the filter membrane. Currently, whether to backflush and the frequency of backflushing are determined only by manual observation of the filter membrane status.

[0004] However, in the prior art, there is a problem of inaccurate recoil triggering. Summary of the invention

[0005] The embodiments of the present application provide an anti-blocking membrane filtration method and an anti-blocking membrane filtration system to achieve the effect of solving the inaccurate recoil triggering problem.

[0006] In a first aspect, an embodiment of the present application provides an anti-blocking membrane filtration method, which is applied to a filtration system, comprising:

[0007] Obtain the pressure of the filter membrane in the filtration system;

[0008] If the pressure of the filter membrane does not meet the preset pressure condition, adjust the frequency of backflushing the filter membrane.

[0009] In a possible implementation, the method further includes:

[0010] If the pressure of the filter membrane does not meet the preset pressure condition, the liquid level of the liquid collecting device in the filtration system is obtained;

[0011] If the liquid level in the liquid collecting device does not meet the liquid level limit value requirement, the filter membrane is backflushed.

[0012] In a possible implementation, before the pressure of the filter membrane fails to meet the preset pressure condition and the frequency of backflushing the filter membrane is adjusted, the method further includes:

[0013] Obtain the filtration cycle and the weight of the filtrate in the filtration system;

[0014] Determine the time point for backflushing based on the relationship between the filtration cycle and the weight of the filtrate;

[0015] Backflush the filter membrane according to the time point for backflush.

[0016] In a possible implementation, determining the time node for backflushing according to the relationship between the filtration cycle and the weight of the filtrate includes:

[0017] Determine the preset division intervals for the weight of the filtrate;

[0018] The time node for backflushing is determined based on the preset division intervals and filtration cycles of the filtrate weight.

[0019] In a possible implementation, the liquid collecting device in the filtration system is communicated with the chamber to be filtered in the filtration system;

[0020] Before backflushing the filter membrane according to the time point for backflushing, the method further includes:

[0021] Determine the preset cross-flow time according to the filtration cycle;

[0022] According to the cross-flow time, the filter chamber is subjected to cross-flow flushing operation.

[0023] In a possible implementation manner, determining the preset cross-flow time according to the filtration cycle includes:

[0024] Get the current weight of the filtration system and the starting weight of the filtration system when adding filtrate;

[0025] According to the ratio of the current weight to the initial weight, the ratio of the preset cross-flow time in the filtration cycle is determined, and the preset cross-flow time is determined.

[0026] In a second aspect, an embodiment of the present application provides an anti-blocking membrane filtration system, the filtration system comprising: a filtration device, the filtration device comprising a chamber to be filtered, a filtered chamber, and a filter membrane disposed between the chamber to be filtered and the filtered chamber, a first inlet of the filtration device connected to the chamber to be filtered is connected to a mortar pipe, a second inlet connected to the chamber to be filtered is connected to a backwash pipe, and a first outlet connected to the filtered chamber is connected to a clear liquid pipe;

[0027] If the pressure of the filter membrane does not meet the preset pressure condition, the opening frequency of the recoil pipe and the closing frequency of the mortar pipe are adjusted, and the opening frequency corresponds to the closing frequency;

[0028] The filter membrane is backflushed according to the opening frequency of the backflushing pipe and the closing frequency of the mortar pipe.

[0029] In a possible implementation manner, the second outlet on the filtering device that is in communication with the chamber to be filtered is in communication with the liquid collecting device through a cross-flow pipe;

[0030] When the first inlet is opened, the first outlet is opened, and the second outlet is closed, the mortar pipe is connected to the clear liquid pipe through the chamber to be filtered, the filter membrane, and the filtered chamber in sequence;

[0031] When the first inlet is opened, the first outlet is closed, and the second outlet is opened, the mortar pipe is connected with the liquid collecting device through the cavity to be filtered and the cross-flow pipe in sequence.

[0032] In a possible embodiment, the third inlet on the filter device that is connected to the filtered chamber is connected to the drain pipe, and the first inlet is also connected to the waste liquid pipe, wherein when the first inlet is opened, the second inlet is opened, and the third inlet is opened, the drain pipe is connected to the backwash pipe through the chamber to be filtered, and the drain pipe is connected to the backwash pipe through the chamber to be filtered and the second inlet in turn, and the waste liquid pipe, the mortar pipe, and the first inlet are connected.

[0033] In a possible implementation manner, the liquid collecting device is further provided with a liquid collecting outlet.

[0034] The embodiment of the present application provides a kind of anti-blocking membrane filtration method and anti-blocking membrane filtration system. The anti-blocking membrane filtration method obtains the pressure of the filter membrane in the filtration system, and then adjusts the frequency of backwashing the filter membrane according to whether the pressure of the filter membrane meets the preset pressure condition, thereby improving the accuracy of backwashing triggering and ensuring that the filter membrane system works under low pressure and high frequency conditions. The anti-blocking membrane filtration system includes a filtration device, the filtration device includes a cavity to be filtered, a filtered cavity, and a filter membrane arranged between the cavity to be filtered and the filtered cavity. The first inlet of the filtration device connected to the cavity to be filtered is connected to the mortar pipe, the second inlet connected to the cavity to be filtered is connected to the backwash pipe, and the first outlet connected to the filtered cavity is connected to the clear liquid pipe. According to the anti-blocking membrane filtration method, the opening frequency of the backwash pipe and the closing frequency of the mortar pipe are adjusted, and the opening frequency corresponds to the closing frequency. According to the opening frequency of the backwash pipe and the closing frequency of the mortar pipe, the filter membrane is backwashed, and the opening efficiency of the backwashing is increased, thereby extending the service life of the filter membrane system. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0036] Figure 1 A schematic diagram of the results of an anti-blocking membrane filtration method before improvement provided in an embodiment of the present application;

[0037] Figure 2 A schematic diagram of a process for preventing blocking of membrane filtration provided in an embodiment of the present application Figure 1 ;

[0038] Figure 3 A schematic diagram of a process for preventing blocking of membrane filtration provided in an embodiment of the present application Figure 2 ;

[0039] Figure 4 A schematic diagram of the structure of an anti-blocking membrane filtration system provided in an embodiment of the present application;

[0040] Figure 4a A schematic diagram of the results of an anti-clogging membrane filtration system provided in an embodiment of the present application.

[0041] The above drawings have shown clear embodiments of the present application, which will be described in more detail later. These drawings and text descriptions are not intended to limit the scope of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments.

[0042] Reference numerals:

[0043] 410 - filtering device; 411 - chamber to be filtered; 412 - filtered chamber;

[0044] 420-liquid collecting device;

[0045] 430- mortar pipe; 440- clear liquid pipe; 450- backwash pipe; 460- cross flow pipe; 470- liquid collection outlet; 480- emptying pipe; 490- waste liquid pipe. DETAILED DESCRIPTION

[0046] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0047] First, the terms involved in this application are explained:

[0048] Filtration system: a device used to separate solid particles and other impurities from liquid or gas. It separates fluid from solid particles by using porous media such as filter screens, filter membranes or filter materials;

[0049] Backflushing: using the reverse flow of fluid to loosen and remove pollutants on the filter medium. The purpose is to remove pollutants and blockages accumulated on the filter medium to restore the filtration efficiency of the filter medium and extend its service life.

[0050] Cross flow: also known as tangential filtration, is a membrane separation technology. It can generate shear force to continuously remove particles retained on the membrane surface, thereby reducing the fouling of the membrane surface and keeping the membrane flux at a thin level;

[0051] Emptying: Air is taken in from the upper end of the filter system so that the residual materials on the filter system are discharged from the lower end of the filter system.

[0052] In the prior art, backwashing is a key step to increase the service life of the filter membrane and maintain the filtration efficiency. Backwashing usually involves simultaneously sending air and backwash water from the bottom of the filter membrane, which can cause the residual substances on the filter membrane to fall off the filter membrane under pressure, thereby enhancing the cleaning effect. The triggering judgment of backwashing is based on manual observation of the filter membrane state, and the decision on whether to backwash is made only when a special situation is approaching, which makes the triggering time of backwashing inaccurate and leads to low efficiency of backwashing.

[0053] An anti-blocking membrane filtration method provided in an embodiment of the present application, in order to improve the accuracy of recoil triggering, by obtaining the pressure of the filter membrane in the filtration system, and adjusting the frequency of recoil on the filter membrane according to the relationship between the pressure of the filter membrane and the preset pressure condition, so as to make corresponding adjustments to the number of recoils according to demand, thereby extending the service life of the filter membrane. In order to further control the frequency of recoil, the liquid level of the liquid collecting device in the filtration system is also obtained, and the frequency of recoil is changed according to the relationship between the liquid level of the liquid collecting device and the liquid level limit value requirement. At the same time, the filter cycle and the weight of the filtrate in the filtration system are used to set a specific number of recoils for the filter membrane to ensure the permeability of the filter membrane, thereby solving the problem of low accuracy of recoil triggering.

[0054] Figure 1 A schematic diagram of the results of an anti-blocking membrane filtration method before improvement provided in an embodiment of the present application, such as Figure 1 As shown, the number of filter membrane cutting knives reflects the service life of the filter membrane. It can be seen that in the prior art, the life of the filter membrane will gradually decrease if backflushing is only performed within a fixed period, and the triggering accuracy of backflushing is not high. A method for anti-blocking membrane filtration provided in an embodiment of the present application can be applied to a filtration system. The scenario of the embodiment of the present application includes: a filter membrane system and a concentrated liquid barrel, wherein the filter membrane system is connected to a mortar pipe, a clear liquid pipe and a backflushing pipe, the concentrated liquid barrel is connected to a filter press pipe, and a concentrated liquid pipe is connected between the filter membrane system and the concentrated liquid barrel.

[0055] The membrane filter system is used to filter mortar waste liquid. The mortar waste liquid enters from the mortar pipe and the clear liquid is discharged from the clear liquid pipe. The concentrated liquid barrel is used to collect the filtered concentrated liquid. When the backwash pipe on the membrane filter system is connected to the backwash water or backwash air flow, the waste residue on the filter membrane falls off the filter membrane, enters the concentrated liquid pipe, and then passes into the concentrated liquid barrel.

[0056] The technical solution of the present application and how the technical solution of the present application solves the above-mentioned technical problems are described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0057] Figure 2 A schematic diagram of a process for preventing blocking of membrane filtration provided in an embodiment of the present application Figure 1 ,like Figure 2 As shown, the method includes:

[0058] S201, obtaining the pressure of the filter membrane in the filtration system.

[0059] Among them, the filter membrane can refer to a material that allows certain substances (such as liquids or gases) to pass through, while blocking or retaining other substances. The filter membrane is selected according to the state of the object to be filtered and the requirements of the filtration speed. For example, the pore size of the microfiltration membrane is smaller and can be used to remove bacteria, yeast and mold. For example, when multi-layer filtration is required, a forward osmosis membrane can be used to achieve water penetration according to the concentration gradient.

[0060] The pressure of the filter membrane refers to the external pressure acting on the filter membrane, which can push the fluid through the filter membrane to achieve the filtration process. The pressure can be measured by a variety of methods, such as direct pressure measurement, using a pressure sensor to measure the pressure difference before and after the filter membrane, and critical flux test, by gradually increasing the pressure and measuring the flux change of the filter membrane until the flux begins to decay, so as to determine the critical flux of the filter membrane.

[0061] In an embodiment of the present application, two pressure sensors are respectively installed in the mortar pipe and the clear liquid pipe, and the pressure of the filter membrane is calculated by measuring the pressure difference between the two pressures, thereby monitoring the operating status of the filtration system, which plays a decisive role in whether backwash is triggered, and can optimize the filtration efficiency and ensure the integrity of the filter membrane.

[0062] S202: If the pressure of the filter membrane does not meet the preset pressure condition, adjust the frequency of backflushing the filter membrane.

[0063] The preset pressure condition is the membrane pressure limit value obtained according to the degree of membrane damage during multiple filtration processes to prevent the filter membrane from being damaged due to excessive pressure caused by accumulation of debris.

[0064] In the embodiment of the present application, a pressure value of 100Kpa is selected as the preset pressure condition. The measured membrane pressure and the preset pressure condition are compared in real time. If the real-time membrane pressure is less than the preset pressure condition, the filter can continue to work. If the real-time membrane pressure is greater than the preset pressure condition, the backwash operation needs to be triggered immediately to increase the frequency of backwashing the membrane, so that the membrane pressure decreases, thereby extending the service life of the membrane. For example, when the measured membrane pressure value is 105Kpa, it means that the membrane pressure value is too large at this time, and backwashing is required to relieve the membrane pressure.

[0065] In some embodiments, the preset pressure conditions are determined based on the characteristics of the filter membrane itself, the filtration speed and the backflushing frequency, wherein the characteristics of the filter membrane itself may refer to the material and structure of the filter membrane, the filtration speed may refer to the amount of liquid passing through the filter membrane per unit time, and the backflushing frequency may refer to the number of times the backflushing operation has been performed.

[0066] The characteristics of the filter membrane itself are determined according to the technical parameters provided by the filter membrane manufacturer. The preset pressure condition can be set to 80% of the maximum working pressure. When the characteristics of the filter membrane itself can withstand higher pressure, the preset pressure condition can be set higher. Conversely, the preset pressure condition is set lower, so that the filter membrane with lower mechanical strength will not be damaged due to excessive pressure, and the service life of the filter membrane is guaranteed to a certain extent. For example, polyethersulfone (PES) can withstand higher pressure due to its higher mechanical strength and thermal stability, so the preset pressure condition can be set relatively high. The maximum working pressure is usually 6bar (0.6MPa) to 10bar (1MPa), and the preset pressure condition can be set to 4.8bar (0.48MPa) to 8bar (0.8MPa).

[0067] The filtration speed affects the pressure of the filter membrane in the filtration system. The higher the filtration speed, the greater the pressure drop when the water flows through the filter membrane, which will cause the system pressure to rise. Therefore, when setting the preset pressure condition, it is necessary to consider the influence of the filtration speed to ensure that even at the maximum filtration speed, the system pressure does not exceed the safe working range of the filter membrane. For example, by installing a flow meter and a differential pressure gauge, the filtration rate and the pressure difference on both sides of the filter membrane can be monitored in real time to determine whether the filtration speed or the preset pressure condition needs to be adjusted. If it is found that the system is often close to the preset pressure condition, it may be due to the filtration speed being too high. At this time, the filtration speed can be appropriately reduced, and the preset pressure condition can be adjusted according to the actual filtration speed to ensure that the system can maintain a safe pressure range while filtering efficiently.

[0068] Recording the frequency of backwashing is essential to maintaining the performance of the filter membrane. If the system is found to be frequently close to the preset pressure condition, the frequency of backwashing can be appropriately increased; otherwise, the frequency of backwashing can be appropriately reduced. As the filtration process proceeds, impurities will gradually accumulate on the surface of the filter membrane, resulting in an increase in filtration resistance and a corresponding increase in system pressure. Backwashing can remove contaminants from the filter membrane, reduce filtration resistance, and restore system pressure to normal. However, backwashing also has costs and resource consumption. Frequent backwashing not only increases energy consumption, but may also shorten the life of the filter membrane. Therefore, it is necessary to arrange the frequency of backwashing reasonably to ensure that while maintaining the performance of the filter membrane, excessive backwashing is avoided. In addition, the preset pressure condition can be reset according to the new filtration conditions after backwashing.

[0069] In some embodiments, the preset pressure condition is set as a dynamic condition according to the type of the filtrate. When the type of the filtrate belongs to the first filtrate, the first preset pressure condition is selected, and when the type of the filtrate belongs to the second filtrate, the second preset pressure condition is selected, wherein the type of the filtrate can be divided into the first filtrate and the second filtrate according to the composition of the filtrate, and the first preset pressure condition is less than the second preset pressure condition.

[0070] The first filter may refer to a filter containing large particles, which will generate greater pressure on the filter membrane during filtration, corresponding to the first preset pressure condition, so that when the pressure of the filter membrane reaches the first preset pressure condition, backwashing can be triggered to reduce the pressure of the filter membrane, thereby ensuring the life of the filter membrane; the second filter may refer to a filter containing small particles, which will generate pressure on the filter membrane relatively slowly during filtration, corresponding to the second preset pressure condition, so that when the pressure of the filter membrane gradually increases to the second preset pressure condition during filtration, backwashing is triggered, thereby increasing the accuracy of triggering backwashing.

[0071] When facing different filtrates, different pressure limit values ​​can make the filter membrane make corresponding adjustments, extending the service life of the filter membrane. For example, if the filter membrane needs to treat a large amount of suspended particles or colloids in the water, a higher pressure may be required to push the water through the filter membrane to ensure water quality. In this case, corresponding to the first preset pressure condition under the first filtrate, the operator can adjust the pressure limit value to maintain the same filtration flux while also protecting the filter membrane.

[0072] In some embodiments, the method further comprises: if the pressure of the filter membrane does not meet the preset pressure condition, obtaining the liquid level of the liquid collecting device in the filtration system;

[0073] If the liquid level in the liquid collecting device does not meet the liquid level limit value requirement, the filter membrane is backflushed.

[0074] The liquid collecting device may refer to a device for storing impurities after filtration, and the liquid collecting device is connected to the filtering device according to the collection requirements.

[0075] The liquid level of the liquid collecting device may refer to the surface height of the liquid in the liquid collecting device, and may reflect the volume of the liquid in the liquid collecting device. The liquid level of the liquid collecting device may be obtained in a variety of ways, such as manually observing the liquid level scale. In the embodiment of the present application, a liquid level meter is installed in the liquid collecting device to monitor the height of the liquid in the liquid collecting device.

[0076] The liquid level limit value requirement may refer to the minimum safety limit value set for the liquid level in the liquid collecting device, to prevent the liquid level in the liquid collecting device from being too low and reducing the filtration efficiency. In the embodiment of the present application, 50L is selected as the liquid level limit value, and the relationship between the real-time measured liquid level and the liquid level limit value is compared to determine whether to backflush the filter membrane. For example, when the measured liquid level is 40L, it means that the liquid collecting device at this time can still accommodate more liquid and can be backflushed, but when the measured liquid level is 52L, it means that the subsequent processing device connected to the liquid collecting device at this time has not yet processed the liquid in the liquid collecting device, so backflushing cannot be performed.

[0077] In some embodiments, before adjusting the frequency of backflushing the filter membrane when the pressure of the filter membrane does not meet the preset pressure condition, the method further includes:

[0078] Obtain the filtration cycle and the weight of the filtrate in the filtration system;

[0079] Determine the time point for backflushing based on the relationship between the filtration cycle and the weight of the filtrate;

[0080] Backflush the filter membrane according to the time point for backflush.

[0081] Among them, the filtration cycle can refer to the time required for an entire filtration process, and the filtration cycle is set according to the filtration requirements. The weight of the filter material can refer to the weight of the filter material placed in the filtration system. The weight of the filter material is limited according to the carrying capacity of the filtration system. The weight of the filter material can be measured before placing it into the filtration system.

[0082] Among them, according to the relationship between the filtration cycle and the weight of the filtrate, the time node for backflushing is determined, including:

[0083] Determine the preset division intervals for the weight of the filtrate;

[0084] The time node for backflushing is determined based on the preset division intervals and filtration cycles of the filtrate weight.

[0085] The time node can refer to a specific time point, and the time node of recoil determines the operation time node of recoil. The time node of recoil can be determined according to the carrying capacity of the filtration system or according to the filtration requirements.

[0086] The preset division intervals may refer to a series of predefined intervals corresponding to different weight intervals, respectively, for distinguishing weight grades of the filtered object.

[0087] In an embodiment of the present application, the preset division intervals can be divided into "first weight", "second weight" and "third weight", the first weight corresponds to a smaller weight interval, the second weight corresponds to an intermediate weight interval, and the third weight corresponds to a larger weight interval. The specific division can be adjusted according to demand. For example, when the weight of the filter is 10Kg, the filtration cycle is selected to be 30min, and the weight of the filter belongs to "small weight filtration", the time node of the recoil can be determined to be once every 10min. When the weight of the filter is 30Kg, the filtration cycle is selected to be 30min, and the weight of the filter belongs to "large weight filtration", the time node of the recoil can be determined to be once every 5min. In the same filtration cycle, the greater the weight, the more times the recoil should be, and for the same weight, the longer the filtration cycle, the fewer times the recoil should be.

[0088] An anti-blocking membrane filtration method provided in an embodiment of the present application automatically adjusts the frequency of backwashing by real-time monitoring of the pressure of the filter membrane and the liquid level of the liquid collecting device to optimize the efficiency of the backwashing and extend the service life of the filter membrane. When the filter membrane pressure exceeds the preset value, the system will automatically increase the frequency of backwashing to reduce the pressure; if the liquid level of the liquid collecting device is lower than the safety limit, backwashing is triggered to prevent the filtration efficiency from decreasing. In addition, combined with the filtration cycle and the weight of the filtrate, the system can more accurately determine the time node of the backwashing, thereby reducing resource waste while ensuring the filtration effect, and improving the operating efficiency and economy of the overall filtration system.

[0089] Figure 3 A schematic diagram of a process for preventing blocking of membrane filtration provided in an embodiment of the present application Figure 2 ,like Figure 3 As shown, before backflushing the filter membrane according to the time point for backflushing, the method further includes:

[0090] S301. Determine a preset cross-flow time according to a filtration cycle.

[0091] The preset cross-flow time may refer to a pre-set cross-flow time. Before backflushing or after normal filtration, a certain time is set for cross-flow operation, which can remove the residues accumulated in the filtration system due to multiple filtrations, thereby increasing the permeability of the filter membrane.

[0092] Wherein, according to the filtration cycle, the preset cross-flow time is determined, including:

[0093] Get the current weight of the filtration system and the starting weight of the filtration system when adding filtrate;

[0094] According to the ratio of the current weight to the initial weight, the ratio of the preset cross-flow time in the filtration cycle is determined, and the preset cross-flow time is determined.

[0095] The current weight of the filtration system can be obtained by using a sensor to measure the weight of the current filtration system and the remaining filtrate. The starting weight can refer to the weight of the filtration system and the filtrate before filtration. In the embodiment of the present application, after measuring the current weight and the starting weight, the current weight is divided by the starting weight to obtain a ratio, and the ratio is multiplied by the filtration cycle to obtain the time required for cross flow at this time. For example, when the filtration cycle is set to 60 minutes, the current weight is measured to be 10Kg, and the starting weight is 50Kg, it can be obtained that the cross flow time required to be preset is 60×(10÷50)=12min.

[0096] S302, performing a cross-flow operation on the filter cavity according to the cross-flow time.

[0097] In the initial stage of normal filtration, the filtration system is operated in cross-flow according to the cross-flow time.

[0098] An anti-blocking membrane filtration method provided in an embodiment of the present application effectively improves the permeability and filtration efficiency of the filter membrane by introducing a cross-flow operation before backflushing. The method first determines a preset cross-flow time according to the filtration cycle. The setting of this time is based on the ratio of the current weight of the filtration system to the starting weight, ensuring that the cross-flow operation is adapted to the weight change of the filtrate. Then, in the initial stage of normal filtration, the filtration system is subjected to a cross-flow operation according to this cross-flow time, and the residue on the surface of the filter membrane is removed by reverse flow to restore the permeability of the filter membrane. This cross-flow operation not only reduces the risk of filter membrane blockage, but also extends the service life of the filter membrane, while improving the efficiency of backflushing and reducing maintenance costs.

[0099] Figure 4 A schematic diagram of the structure of an anti-blocking membrane filtration system provided in an embodiment of the present application is shown in FIG. Figure 4 As shown, the execution body of an anti-blocking membrane filtration system provided in an embodiment of the present application can be a processor, and the embodiment of the present application does not limit the processor. As long as the processor can include: a filter device 410, the filter device 410 includes a chamber to be filtered 411, a filtered chamber 412, and a filter membrane arranged between the chamber to be filtered 411 and the filtered chamber 412, the first inlet of the filter device 410 connected to the chamber to be filtered 411 is connected to the mortar pipe 430, the second inlet connected to the chamber to be filtered 411 is connected to the backwash pipe 450, and the first outlet connected to the filtered chamber 412 is connected to the clear liquid pipe 440, wherein,

[0100] The filter device 410 may refer to a device used to separate solid particles and other impurities in liquid or gas. The filter device 410 may be selected according to the filtering requirements and the state of the filtered object, and may be composed of the most basic filtering instruments, such as a funnel and filter paper for filtering liquid. The filter device 410 may also be composed of a membrane filter device 410 for filtering microorganisms, macromolecular organic matter and ions in water.

[0101] The cavity to be filtered 411 may refer to a cavity in the filter device 410 that temporarily stores the object to be filtered, in preparation for filtering. The cavity to be filtered 411 may be changed according to the shape and size of the object to be filtered, and according to the filtering speed of the filter device 410. For example, when filtering particulate impurities in a liquid, a funnel and filter paper may be used for filtering, and the cavity to be filtered 411 may be changed according to the shape of the funnel. When the cavity to be filtered 411 is a cone, the filtered liquid may enter from the bottom of the cone and leak out from the tip, thereby improving the filtering speed and efficiency.

[0102] The filtered cavity 412 may refer to a cavity in the filter device 410 that temporarily stores the filtered material, and is used to store the filtered material. The filtered cavity 412 may be connected to the to-be-filtered cavity 411 through a filtering device. The filtered cavity 412 is consistent with the to-be-filtered cavity 411, and may change shape according to the requirements of the filter device 410. For example, when filtering liquid, when the liquid becomes clear liquid after passing through the filtering device, the inlet of the filtered cavity 412 may be slightly larger than the outlet of the to-be-filtered cavity 411, so as to facilitate storage of the filtered material.

[0103] In the embodiment of the present application, the chamber to be filtered 411 refers to a plurality of columnar structures in the filter device 410, the column body is surrounded by a filter membrane, and the filter membrane is made of a special molecular material, which can trap impurities such as sand and gravel in the mortar waste liquid and allow the liquid to pass through. The filtered chamber 412 can refer to the cavity part of the filter device 410 that wraps the chamber to be filtered 411. After the liquid passes through the filter membrane, it remains in the filtered chamber 412.

[0104] The mortar pipe 430 may refer to a pipe for pouring mortar waste liquid, and the first inlet may refer to an interface between the mortar pipe 430 and the chamber to be filtered 411. When the mortar waste liquid enters from the mortar pipe 430, it enters the chamber to be filtered 411 through the first inlet and remains in the chamber to be filtered 411 to wait for filtration. A mortar valve is provided on the mortar pipe 430 to control the entry of the mortar waste liquid and the flow rate of the mortar waste liquid.

[0105] The backflushing pipe 450 may refer to a pipe for introducing backflushing water or backflushing airflow, and the second inlet may refer to the interface between the backflushing pipe 450 and the chamber to be filtered 411. When the backflushing water or backflushing airflow enters from the backflushing pipe 450, it enters the chamber to be filtered 411 through the second inlet, and the chamber to be filtered 411 is subjected to pressure, so that the filter membrane is squeezed, and the residual impurities on the filter membrane fall off the filter membrane.

[0106] The clear liquid pipe 440 can refer to a pipe for collecting the clear liquid after filtration, and the first outlet can refer to the interface between the clear liquid pipe 440 and the filtered chamber 412. After the mortar waste liquid is filtered, the clear liquid is filtered out from the filter membrane and enters the filtered chamber 412, and then enters the clear liquid pipe 440 through the first outlet, and finally enters the container for storing the clear liquid. The container can be selected according to needs and is not limited here.

[0107] In some embodiments, the filtration system performs a backwashing operation, and backwashing water or backwashing airflow is introduced from the backwashing pipe 450, and the high-pressure backwashing water or backwashing airflow enters the cavity to be filtered 411, so that the filter membrane of the outer layer of the cavity to be filtered 411 is flushed, and the residual substances on the filter membrane fall off, wherein,

[0108] If the pressure of the filter membrane does not meet the preset pressure condition, the opening frequency of the backwash pipe 450 and the closing frequency of the mortar pipe 430 are adjusted, and the opening frequency corresponds to the closing frequency;

[0109] The filter membrane is backflushed according to the opening frequency of the backflushing pipe 450 and the closing frequency of the mortar pipe 430 .

[0110] The opening frequency may refer to the number of times the recoil tube 450 is opened. The opening frequency may be set as required. In an embodiment of the present application, if the membrane pressure exceeds a preset pressure condition, the opening frequency is increased and a recoil operation is performed to prevent damage to the membrane.

[0111] The closing frequency may refer to the number of times the mortar tube 430 is closed. The closing frequency may be set as required. In the embodiment of the present application, the closing frequency is consistent with the opening frequency. When a recoil operation is required, the mortar tube 430 is closed and the recoil tube 450 is opened to improve the recoil efficiency.

[0112] In some embodiments, the second outlet of the filter device 410 connected to the chamber to be filtered 411 is connected to the liquid collecting device 420 through the cross-flow tube 460. When the first inlet is opened, the first outlet is opened, and the second outlet is closed, the mortar tube 430 is connected to the clear liquid pipe 440 through the chamber to be filtered 411, the filter membrane, and the filtered chamber 412 in sequence; when the first inlet is opened, the first outlet is closed, and the second outlet is opened, the mortar tube 430 is connected to the liquid collecting device 420 through the chamber to be filtered 411 and the cross-flow tube 460 in sequence, wherein:

[0113] The cross-flow tube 460 may refer to a pipe for discharging the cross-flow liquid, and the second outlet may refer to the interface between the cross-flow tube 460 and the chamber to be filtered 411. A cross-flow valve is provided on the cross-flow tube 460. When a cross-flow operation is required, the cross-flow valve is opened, and the mortar liquid enters from the mortar tube 430, passes through the chamber to be filtered 411 into the second outlet, and flows into the cross-flow tube 460, taking away the residues accumulated on the upper part of the chamber to be filtered 411 due to multiple filtrations, thereby increasing the permeability of the filter membrane.

[0114] In the embodiment of the present application, the liquid collecting device 420 is connected to the first inlet of the filtering device 410 through the liquid collecting pipe, and the liquid collecting pipe and the mortar pipe 430 are connected, so that impurities after backflushing can be collected, and the waste liquid of the mortar waste liquid that has not entered the filtering device 410 can be collected. In addition, the liquid collecting device 420 is also connected to the filtering device 410 through the cross-flow pipe 460. When the cross-flow operation is performed, the liquid in the cross-flow pipe 460 also enters the liquid collecting device 420.

[0115] In some embodiments, the third inlet on the filter device 410 connected to the filtered chamber 412 is connected to the drain pipe 480, and the first inlet is also connected to the waste pipe 490, wherein, when the first inlet is opened, the second inlet is opened, and the third inlet is opened, the drain pipe 480 is connected to the backwash pipe 450 through the chamber to be filtered 411, and the drain pipe 480 is connected to the backwash pipe 450 through the chamber to be filtered 411 and the second inlet in turn, and the waste pipe 490, the mortar pipe 430 and the first inlet are connected, wherein,

[0116] The drain pipe 480 may refer to a pipe for introducing air, which is used for draining after backflushing, so that the residues remaining after backflushing are further drained. The third inlet may refer to the interface between the drain pipe 480 and the chamber to be filtered 411. A drain valve is left on the drain pipe 480. When draining is required, the drain valve is opened to introduce air from the drain pipe 480, so that the residues on the filter membrane fall off due to pressure.

[0117] In some embodiments, the evacuation tube 480 and the backflushing tube 450 are arranged diagonally to allow gas convection, thereby squeezing the residue on the filter membrane more fully and improving the backflushing efficiency.

[0118] In the embodiment of the present application, a liquid collecting outlet 470 is also provided on the liquid collecting device 420, wherein the liquid collecting outlet 470 may refer to an outlet on the liquid collecting device 420 for discharging liquid, and the liquid collecting outlet 470 is connected to a filter press device, which may be used for filtering waste liquid, such as a chamber filter press or a vertical filter press, which is not limited in the embodiment of the present application.

[0119] An anti-blocking membrane filtration system provided by an embodiment of the present application realizes an efficient filtration and cleaning process through a filter device 410 and a pipeline configuration. The system includes a chamber to be filtered 411, a filtered chamber 412 and a filter membrane, and is connected to the outside through multiple pipelines, including a mortar pipe 430, a backwash pipe 450, a clear liquid pipe 440, a cross-flow pipe 460 and an emptying pipe 480. By controlling the valves of these pipelines, the system can perform precise fluid control at different operation stages. The backwash operation adjusts the opening frequency of the backwash pipe 450 and the closing frequency of the mortar pipe 430 to adapt to the changes in the filter membrane pressure, thereby preventing the filter membrane from being damaged and improving the cleaning efficiency. The cross-flow operation discharges the residue through the cross-flow pipe 460 to enhance the permeability of the filter membrane. The emptying operation uses the emptying pipe 480 to further remove the residue on the filter membrane and improve the cleaning effect. In addition, the system is also equipped with a liquid collecting device 420, which collects filtered impurities and waste liquid through a waste liquid pipe 490 and a cross-flow pipe 460, and connects to a filter press through a liquid collecting outlet 470 for further processing. Overall, the design of this filtration system improves the backwashing efficiency during filtration, reduces the risk of membrane clogging, and simplifies the maintenance process, providing an efficient and reliable solution for industrial filtration applications. Figure 4a It can be seen that as the recoil progresses, the number of cutters on the filter membrane first increases and then tends to stabilize, indicating that the service life of the filter membrane is extended and the triggering accuracy of the recoil is greatly improved.

[0120] Finally, it should be noted that those skilled in the art will readily conceive of other embodiments of the present invention after considering the specification and practicing the invention disclosed herein. The present invention is intended to cover any variations, uses or adaptations of the present invention, which follow the general principles of the present invention and include common knowledge or customary technical means in the art not disclosed by the present invention, are not limited to the precise structure described above and shown in the drawings, and may be modified and changed in various ways without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

Claims

1. A method for anti-blocking membrane filtration, characterized in that: Applied to a filtration system, the method comprises: Obtaining the pressure of the filter membrane in the filtration system; If the pressure of the filter membrane does not meet the preset pressure condition, the frequency of backflushing the filter membrane is adjusted.

2. The method according to claim 1, characterized in that: The method further comprises: If the pressure of the filter membrane does not meet the preset pressure condition, obtaining the liquid level of the liquid collecting device in the filtration system; If the liquid level of the liquid collecting device does not meet the liquid level limit value requirement, the filter membrane is backflushed.

3. The method according to claim 1, characterized in that: Before adjusting the frequency of backflushing the filter membrane when the pressure of the filter membrane does not meet the preset pressure condition, the method further includes: Obtain the filtration cycle and the weight of the filtrate in the filtration system; Determining a time point for backflushing based on the relationship between the filtration cycle and the weight of the filtrate; The filter membrane is backflushed according to the time point for backflushing.

4. The method according to claim 3, characterized in that Determining a time point for backflushing based on the relationship between the filtration cycle and the weight of the filtrate includes: Determining a preset division interval for the weight of the filtrate; The time node for backflushing is determined according to the preset division intervals of the filter weight and the filtering cycle.

5. The method according to claim 3, characterized in that: Before backflushing the filter membrane according to the time point for backflushing, the method further includes: Determine the preset cross-flow time according to the filtration cycle; According to the cross-flow time, a cross-flow operation is performed on the cavity to be filtered.

6. The method according to claim 5, characterized in that Determining the preset cross-flow time according to the filtration cycle includes: Obtaining the current weight of the filtration system and the starting weight of the filtration system when adding filtrate; According to the ratio of the current weight to the starting weight, the ratio of the preset cross-flow time in the filtration cycle is determined, and the preset cross-flow time is determined.

7. An anti-blocking membrane filtration system, characterized in that: The filtration system comprises: a filtration device, the filtration device comprises a chamber to be filtered, a filtered chamber, and a filter membrane disposed between the chamber to be filtered and the filtered chamber, a first inlet of the filtration device communicating with the chamber to be filtered is connected to a mortar pipe, a second inlet communicating with the chamber to be filtered is connected to a backwash pipe, and a first outlet communicating with the filtered chamber is connected to a clear liquid pipe; Wherein, if the pressure of the filter membrane does not meet the preset pressure condition, the opening frequency of the recoil pipe and the closing frequency of the mortar pipe are adjusted, and the opening frequency corresponds to the closing frequency; The filter membrane is backflushed according to the opening frequency of the backflushing pipe and the closing frequency of the mortar pipe.

8. The system according to claim 7, characterized in that The second outlet on the filtering device that is in communication with the chamber to be filtered is in communication with the liquid collecting device through a cross-flow pipe; Wherein, when the first inlet is opened, the first outlet is opened, and the second outlet is closed, the mortar pipe is connected to the clear liquid pipe through the chamber to be filtered, the filter membrane, and the filtered chamber in sequence; When the first inlet is opened, the first outlet is closed, and the second outlet is opened, the mortar pipe is connected to the liquid collecting device through the cavity to be filtered and the cross-flow pipe in sequence.

9. The system according to claim 7, characterized in that The third inlet on the filtering device that is connected to the filtered chamber is connected to the drain pipe, and the first inlet is also connected to the waste liquid pipe, wherein when the first inlet is opened, the second inlet is opened, and the third inlet is opened, the drain pipe is connected to the backwash pipe through the chamber to be filtered, and the drain pipe is connected to the backwash pipe through the chamber to be filtered and the second inlet in turn, and the waste liquid pipe, the mortar pipe, and the first inlet are connected.

10. The system according to claim 8, characterized in that The liquid collecting device is also provided with a liquid collecting outlet.

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