Membrane filtration system and method of operating the same

Abstract

The application relates to the technical field of bioengineering, and provides a membrane filtration system and a running method thereof, wherein the membrane filtration system comprises a control mainboard, a water inlet pipeline, a raw solution feeding pipeline, a raw solution tank, a raw solution discharging pipeline, a membrane assembly, a raw solution return pipeline, a clear solution discharging pipeline and a clear solution tank; the water inlet pipeline and the raw solution feeding pipeline are communicated with the raw solution tank, the raw solution tank is communicated with the membrane assembly through the raw solution discharging pipeline, the membrane assembly is communicated with the raw solution tank through the raw solution return pipeline, and the clear solution tank is communicated with the membrane assembly through the clear solution discharging pipeline; the control mainboard is configured to open the water inlet pipeline according to the liquid level value of the material in the raw solution tank, close the water inlet pipeline according to the solid content value of the clear solution detected on the clear solution discharging pipeline, and close the membrane filtration system according to the flow value of the clear solution detected on the clear solution discharging pipeline. In this way, the material state in operation can be automatically monitored and judged, corresponding adjustment can be automatically completed, and the automatic control of the microbial fermentation liquid separation process is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of bioengineering, and particularly relates to a membrane filtration system and a running method thereof. BACKGROUND

[0002] In the field of microbial fermentation, after the fermentation process is completed, a purification process is entered, in which the separation of bacteria is usually achieved by using microfiltration membrane separation technology; and for the removal of macromolecular substances (such as proteins, nucleic acids, endotoxins, etc.), ultrafiltration membrane separation technology is generally used. However, during the operation of the membrane machine, manual water addition backwashing operation is required, and the determination of the separation end point needs to be detected by sampling and relied on manual judgment, which is easy to produce different results due to the difference in personnel operation. SUMMARY

[0003] The present application provides a membrane filtration system and a running method thereof, aiming at solving the problem in the prior art that manual water addition backwashing needs to be manually performed in the membrane filtration operation, and the separation end point determination relies on sampling detection and manual judgment, which is easy to cause inconsistent results due to the difference in personnel operation.

[0004] The present application provides a membrane filtration system, comprising: a control mainboard, a water inlet pipeline, a raw liquid feeding pipeline, a raw liquid tank, a raw liquid discharging pipeline, a membrane assembly, a raw liquid return pipeline, a clear liquid discharging pipeline and a clear liquid tank.

[0005] The water inlet pipeline and the raw liquid feeding pipeline are both in communication with the raw liquid tank, the raw liquid tank is in communication with the membrane assembly through the raw liquid discharging pipeline, the membrane assembly is in communication with the raw liquid tank through the raw liquid return pipeline, and the clear liquid tank is in communication with the membrane assembly through the clear liquid discharging pipeline; wherein the control mainboard is configured to open the water inlet pipeline according to the liquid level value of the material in the raw liquid tank, close the water inlet pipeline according to the solid content value of the clear liquid detected on the clear liquid discharging pipeline, and close the membrane filtration system according to the flow value of the clear liquid detected on the clear liquid discharging pipeline.

[0006] According to the membrane filtration system provided by the present application, the water inlet pipeline is provided with a first pneumatic on-off valve, the raw liquid tank is provided with a first liquid level measuring instrument, the clear liquid discharging pipeline is provided with a solid content measuring instrument and a first flow measuring instrument, and the first pneumatic on-off valve, the first liquid level measuring instrument, the solid content measuring instrument and the first flow measuring instrument are all electrically connected with the control mainboard.

[0007] According to the membrane filtration system provided by the application, the raw liquid outlet pipeline is provided with a pump body and a first pressure transmitter, and the pump body and the first pressure transmitter are sequentially arranged along the material flow direction of the raw liquid outlet pipeline; the raw liquid return pipeline is provided with a second pressure transmitter, a first pneumatic regulating valve and a second flow measuring instrument, and the second pressure transmitter, the first pneumatic regulating valve and the second flow measuring instrument are sequentially arranged along the material flow direction of the raw liquid return pipeline; wherein the pump body, the first pressure transmitter, the second pressure transmitter, the first pneumatic regulating valve and the second flow measuring instrument are electrically connected with the control mainboard.

[0008] According to the membrane filtration system provided by the application, the raw liquid return pipeline is provided with a heat exchange pipeline and a first temperature measuring instrument, and the heat exchange pipeline and the first temperature measuring instrument are sequentially arranged along the material flow direction of the raw liquid return pipeline; wherein the control mainboard is further configured to control the heat exchange pipeline to adjust the temperature of the material flowing through the raw liquid return pipeline, so that the temperature value of the first temperature measuring instrument is equal to the target temperature value.

[0009] According to the membrane filtration system provided by the application, the heat exchange pipeline comprises a cooler, a first cooling liquid branch and a second cooling liquid branch, the cooler has a material channel and a cooling liquid channel, the material channel is communicated with the raw liquid return pipeline, and the first cooling liquid branch and the second cooling liquid branch are both communicated with the cooling liquid channel; wherein the first cooling liquid branch is provided with a second pneumatic on-off valve and a second pneumatic regulating valve, and the second pneumatic on-off valve and the second pneumatic regulating valve are sequentially arranged along the material flow direction of the first cooling liquid branch; the second cooling liquid branch is provided with a third pneumatic on-off valve; and the second pneumatic on-off valve, the second pneumatic regulating valve and the third pneumatic on-off valve are electrically connected with the control mainboard.

[0010] According to the membrane filtration system provided by the application, the membrane filtration system further comprises a first liquid inlet branch and a first blowdown branch, the first liquid inlet branch is communicated with the raw liquid tank, and the raw liquid outlet pipeline is further provided with a fourth pneumatic on-off valve; along the material flow direction of the raw liquid return pipeline, the connection point of the first blowdown branch on the raw liquid outlet pipeline is located on the upstream side of the fourth pneumatic on-off valve; the first liquid inlet branch is provided with a fifth pneumatic on-off valve, the first blowdown branch is provided with a sixth pneumatic on-off valve, and the fourth pneumatic on-off valve, the fifth pneumatic on-off valve and the sixth pneumatic on-off valve are electrically connected with the control mainboard.

[0011] According to the membrane filtration system provided by the application, the second liquid inlet branch is connected to the raw liquid outlet pipeline at a position downstream of the fourth pneumatic switch valve, and the seventh pneumatic switch valve is arranged on the second liquid inlet branch.

[0012] According to the membrane filtration system provided by the application, the manual switch valve is arranged on the clear liquid outlet pipeline and located upstream of the third pressure transmitter.

[0013] The application further provides a running method of the membrane filtration system, comprising the following steps.

[0014] The raw liquid inlet pipeline is opened to allow the material to enter the raw liquid tank, and the material is circulated between the raw liquid tank and the membrane assembly, and the clear liquid is collected through the clear liquid tank.

[0015] The water inlet pipeline is opened according to the liquid level value of the material in the raw liquid tank, and the water inlet pipeline is closed according to the solid content value of the clear liquid detected on the clear liquid outlet pipeline.

[0016] The membrane filtration system is closed according to the flow value of the clear liquid detected on the clear liquid outlet pipeline.

[0017] According to the running method of the membrane filtration system provided by the application, the circulation of the material between the raw liquid tank and the membrane assembly comprises the following steps.

[0018] The pump body is opened, and the working frequency of the pump body is adjusted to a target working frequency.

[0019] The opening degree of the first pneumatic regulating valve is adjusted to make the flow value of the second flow measuring instrument equal to a target flow value or the pressure value of the second pressure transmitter equal to a target pressure value.

[0020] The membrane filtration system and the operation method thereof provided by the application include a raw liquid feeding pipeline, a raw liquid tank, a raw liquid discharging pipeline, a raw liquid return pipeline, a water feeding pipeline, a membrane module, a clear liquid discharging pipeline, a control mainboard and a control system. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are some embodiments of the application, and other drawings can also be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0022] Figure 1 FIG. 1 is a structural schematic diagram of the membrane filtration system provided by the application.

[0023] Figure 2 FIG. 2 is a flow chart of the operation method of the membrane filtration system provided by the application.

[0024] REFERENCE NUMERALS:

[0025] 1, stock solution tank; 11, containing space; 12, stirrer; 13, first PH sensor; 14, second temperature measuring instrument; 15, first liquid level measuring instrument; 2, stock solution discharge pipeline; 21, fourth pneumatic on-off valve; 22, pump body; 23, first pressure transmitter; 24, seventh pneumatic on-off valve; 25, second liquid inlet branch; 26, sixth pneumatic on-off valve; 27, first blowdown branch; 3, membrane module; 4, stock solution return pipeline; 41, second pressure transmitter; 42, first pneumatic regulating valve; 43, second flow measuring instrument; 44, cooler; 45, first cooling liquid branch; 46, second pneumatic on-off valve; 47, second pneumatic regulating valve; 48, second cooling liquid branch; 49, third pneumatic on-off valve; 410, first temperature measuring instrument; 411, ninth pneumatic on-off valve; 412, second blowdown branch; 413, eighth pneumatic on-off valve; 5, stock solution feed pipeline; 51, twelfth pneumatic on-off valve; 6, water inlet pipeline; 61, first pneumatic on-off valve; 62, third flow measuring instrument; 7, clear solution discharge pipeline; 71, first manual switch; 72, second manual switch; 73, first flow measuring instrument; 74, third pressure transmitter; 75, solid content measuring instrument; 76, second PH sensor; 77, tenth pneumatic on-off valve; 78, eleventh pneumatic on-off valve; 79, third blowdown branch; 8, clear solution tank; 81, second liquid level measuring instrument; 9, first liquid inlet branch; 91, fifth pneumatic on-off valve; 92, spray ball. DETAILED DESCRIPTION

[0026] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions in the present application will be described clearly and completely below with reference to the drawings in the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of the present application.

[0027] As Figure 1As shown, the membrane filtration system of the embodiment of the present application can be used to separate the microbial cells and macromolecules in the microbial fermentation broth. The membrane filtration system comprises a control mainboard, a water inlet pipeline 6, a raw liquid feeding pipeline 5, a raw liquid tank 1, a raw liquid outlet pipeline 2, a membrane module 3, a raw liquid return pipeline 4, a clear liquid outlet pipeline 7 and a clear liquid tank 8. The clear liquid tank 8 can be provided with a second liquid level measuring instrument 81 for detecting the liquid level value of the clear liquid in the clear liquid tank 8. The water inlet pipeline 6 and the raw liquid feeding pipeline 5 are both in communication with the raw liquid tank 1. The raw liquid tank 1 is in communication with the membrane module 3 through the raw liquid outlet pipeline 2. The membrane module 3 is in communication with the raw liquid tank 1 through the raw liquid return pipeline 4. The clear liquid tank 8 is in communication with the membrane module 3 through the clear liquid outlet pipeline 7. The control mainboard is configured to open the water inlet pipeline 6 according to the liquid level value of the material in the raw liquid tank 1, to close the water inlet pipeline 6 according to the solid content value of the clear liquid detected on the clear liquid outlet pipeline 7, and to close the membrane filtration system according to the flow value of the clear liquid detected on the clear liquid outlet pipeline 7.

[0028] It should be noted that the membrane module 3 can be a microfiltration membrane or an ultrafiltration membrane. The microfiltration membrane is generally a ceramic membrane or a hollow fiber membrane. The ultrafiltration membrane is generally a spiral membrane or a hollow fiber membrane. The microfiltration membrane is used for filtering the microbial cells in the fermentation broth. The ultrafiltration membrane is used for filtering the clear liquid after the microfiltration membrane to remove macromolecules such as proteins, nucleic acids and endotoxins.

[0029] Specifically, the water inlet pipeline 6 and the raw liquid feeding pipeline 5 are respectively sealed and connected to the corresponding interfaces of the raw liquid tank 1 to ensure that there is no leakage at the connection. The raw liquid tank 1 is tightly connected to the feeding port of the membrane module 3 through the raw liquid outlet pipeline 2. The return port of the membrane module 3 is in communication with the raw liquid tank 1 through the raw liquid return pipeline 4 to form a circulating loop of the raw liquid. The clear liquid tank 8 is connected to the clear liquid outlet of the membrane module 3 through the clear liquid outlet pipeline 7 to collect the filtered clear liquid.

[0030] In actual application, the raw liquid to be filtered is introduced into the raw liquid tank 1 by opening the raw liquid feeding pipeline 5. When the raw liquid in the raw liquid tank 1 reaches a certain amount, the raw liquid feeding pipeline 5 is closed and the filtration program is started. At the same time, the liquid level value of the material in the raw liquid tank 1 is monitored in real time and transmitted to the control mainboard. According to the preset program, the control mainboard determines whether the liquid level of the material in the raw liquid tank 1 reaches the set value for opening the water inlet pipeline 6. When the set value is reached, the control mainboard issues an instruction to open the water inlet pipeline 6 to add water to the raw liquid tank 1. After a certain amount of water is added to the raw liquid tank 1, the raw liquid outlet pipeline 2, the raw liquid return pipeline 4 and the clear liquid outlet pipeline 7 are continuously opened. The material in the raw liquid tank 1 enters the membrane module 3 through the raw liquid outlet pipeline 2 for further filtration.

[0031] It is particularly pointed out that, in the whole filtration process, the solid content value of the clear liquid in the clear liquid discharge pipeline 7 is detected in real time, and the solid content value is transmitted to the control mainboard. In addition, the flow value of the clear liquid in the clear liquid discharge pipeline 7 is detected in real time, and the flow value is transmitted to the control mainboard. The control mainboard compares the received clear liquid solid content value with the preset solid content threshold value for closing the water inlet pipeline 6. When the detected clear liquid solid content value reaches the preset threshold value, the control mainboard issues an instruction to close the water inlet pipeline 6 and stop adding water to the raw liquid tank 1. The control mainboard continues to monitor the flow value of the clear liquid in the clear liquid discharge pipeline 7 and compares it with the preset flow threshold value for closing the membrane filtration system. When the detected clear liquid flow value is lower than the preset threshold value, the control mainboard issues an instruction to stop the operation of the membrane filtration system. In this way, the material state during operation can be automatically monitored and judged, and the corresponding adjustment can be automatically completed, thereby realizing the automatic control of the microbial fermentation liquid separation process.

[0032] As an example, as shown in Figure 1 , the water inlet pipeline 6 is provided with a first pneumatic on-off valve 61, the raw liquid tank 1 is provided with a first liquid level measuring instrument 15, the clear liquid discharge pipeline 7 is provided with a solid content measuring instrument 75 and a first flow measuring instrument 73, and the first pneumatic on-off valve 61, the first liquid level measuring instrument 15, the solid content measuring instrument 75 and the first flow measuring instrument 73 are electrically connected with the control mainboard. Exemplarily, the number of first liquid level measuring instruments can be multiple, and the multiple first liquid level measuring instruments 15 are sequentially arranged along the height direction of the raw liquid tank 1.

[0033] Among them, the raw liquid feeding pipeline 5 is provided with a twelfth pneumatic on-off valve 51, and the water inlet pipeline 6 is further provided with a third flow measuring instrument 62, and the third flow measuring instrument 62 and the first pneumatic on-off valve 61 are sequentially arranged along the material flow direction of the water inlet pipeline 6. The raw liquid tank 1 is further provided with a first PH value sensor 13 and a second temperature measuring instrument 14, so as to detect the PH value and temperature value of the material in the raw liquid tank 1. In addition, the raw liquid tank 1 is provided with a containing space 11, and a stirrer 12 is arranged in the containing space 11, and the stirrer 12 is used to make the material in the containing space 11 always in a uniform state.

[0034] In an optional embodiment, as shown in Figure 1 , the raw liquid discharge pipeline 2 is provided with a pump body 22 and a first pressure transmitter 23, and the pump body 22 and the first pressure transmitter 23 are sequentially arranged along the material flow direction of the raw liquid discharge pipeline 2; the raw liquid return pipeline 4 is provided with a second pressure transmitter 41, a first pneumatic regulating valve 42 and a second flow measuring instrument 43, and the second pressure transmitter 41, the first pneumatic regulating valve 42 and the second flow measuring instrument 43 are sequentially arranged along the material flow direction of the raw liquid return pipeline 4; wherein the pump body 22, the first pressure transmitter 23, the second pressure transmitter 41, the first pneumatic regulating valve 42 and the second flow measuring instrument 43 are electrically connected with the control mainboard.

[0035] It should be noted that the first pressure transmitter 23 monitors the pressure value in the raw liquid discharge pipeline 2 in real time and feeds back the data to the control mainboard. The control mainboard determines whether the current pressure is normal according to the preset pressure range. If the pressure is too high, there may be problems such as excessive output of the pump body 22 or blockage of the membrane assembly 3; if the pressure is too low, it may be caused by pump body 22 failure or pipeline leakage. When the pressure exceeds the preset range, the control mainboard will issue an alarm and take appropriate adjustment measures. The pump body 22 can be a variable frequency pump.

[0036] It can be understood that the second pressure transmitter 41 monitors the pressure value in the raw liquid return pipeline 4 in real time, and the second flow measuring instrument 43 monitors the flow value in the raw liquid return pipeline 4 in real time, and transmits the data to the control mainboard. If the pressure is too high or the flow is too large, the control mainboard will send instructions to the first pneumatic regulating valve 42 to reduce the opening of the valve and reduce the flow and pressure in the raw liquid return pipeline 4; on the contrary, if the pressure is too low or the flow is too small, the opening of the valve will be increased to increase the flow and pressure. Through such dynamic adjustment, the pressure and flow in the raw liquid return pipeline 4 are always kept within a suitable range, improving the efficiency and stability of membrane filtration. That is, the working mode of the membrane filtration system can be selected as constant pressure mode or constant flow mode.

[0037] In order to realize accurate regulation and control of the temperature of the material flowing through the raw liquid return pipeline 4, in the optional embodiment, as shown in Figure 1 , the raw liquid return pipeline 4 is provided with a heat exchange pipeline and a first temperature measuring instrument 410, which are sequentially arranged along the material flow direction of the raw liquid return pipeline 4; wherein the control mainboard is further configured to control the heat exchange pipeline to adjust the temperature of the material flowing through the raw liquid return pipeline 4, so that the temperature value of the first temperature measuring instrument 410 is equal to the target temperature value. Specifically, along the material flow direction of the raw liquid return pipeline 4, the heat exchange pipeline is located on the downstream side of the second flow measuring instrument 43.

[0038] As an example, the heat exchange pipeline includes a cooler 44, a first cooling liquid branch 45 and a second cooling liquid branch 48, the cooler 44 has a material passage and a cooling liquid passage, the material passage communicates with the raw liquid return pipeline 4, and the first cooling liquid branch 45 and the second cooling liquid branch 48 both communicate with the cooling liquid passage; wherein the first cooling liquid branch 45 is provided with a second pneumatic on-off valve 46 and a second pneumatic regulating valve 47, which are sequentially arranged along the material flow direction of the first cooling liquid branch 45; the second cooling liquid branch 48 is provided with a third pneumatic on-off valve 49; the second pneumatic on-off valve 46, the second pneumatic regulating valve 47 and the third pneumatic on-off valve 49 are all electrically connected with the control mainboard.

[0039] Specifically, the higher-temperature material exiting membrane module 3 flows into the material channel of cooler 44. Within the channel, it transfers heat to cooler 44, lowering its own temperature, and then returns to the raw material tank 1 via the raw material return pipe 4. The low-temperature coolant is pumped into the coolant channel of cooler 44 via the first coolant branch 45. Within the channel, it absorbs heat from the material, raising its own temperature and becoming a high-temperature coolant. The high-temperature coolant is discharged via the second coolant branch 48, thus continuously "transferring" heat away from the system.

[0040] It should be noted that when the system requires cooling, the control board opens the second pneumatic switch valve 46, allowing coolant to flow in. When cooling is not required, it closes, completely cutting off the coolant supply. The second pneumatic regulating valve 47, located after the second pneumatic switch valve 46, receives signals from the control board and continuously and precisely adjusts the valve opening, thereby controlling the coolant flow rate. The larger the opening, the greater the flow rate and the stronger the cooling capacity. The third pneumatic switch valve 49 is linked to the second pneumatic switch valve 46, opening and closing simultaneously.

[0041] In practical applications, if the actual temperature is higher than the target temperature, it indicates insufficient material cooling. The main control board will issue a command to increase the opening of the second pneumatic regulating valve 47 on the first coolant branch 45, allowing more coolant to flow through the heat exchanger, thereby enhancing the cooling effect and lowering the material temperature. If the actual temperature is lower than the target temperature, it indicates over-cooling. The main control board will decrease the opening of the second pneumatic regulating valve 47, reducing the coolant flow and weakening the cooling effect, causing the material temperature to rise. If the actual temperature equals the target temperature, the current opening of the second pneumatic regulating valve 47 will remain unchanged.

[0042] In optional embodiments, such as Figure 1 As shown, the membrane filtration system also includes a first inlet branch 9 and a first drain branch 27. The first inlet branch 9 is connected to the raw liquid tank 1, and the raw liquid discharge pipeline 2 is also equipped with a fourth pneumatic switch valve 21. Along the material flow direction of the raw liquid return pipeline 4, the connection point of the first drain branch 27 on the raw liquid discharge pipeline 2 is located upstream of the fourth pneumatic switch valve 21. The first inlet branch 9 is equipped with a fifth pneumatic switch valve 91, and the first drain branch 27 is equipped with a sixth pneumatic switch valve 26. The fourth pneumatic switch valve 21, the fifth pneumatic switch valve 91, and the sixth pneumatic switch valve 26 are all electrically connected to the control main board.

[0043] Specifically, along the material flow direction of the raw liquid discharge pipeline 2, the fourth pneumatic switch valve 21, the pump body 22, and the first pressure transmitter 23 are sequentially arranged. The first liquid inlet branch 9 is also equipped with a spray ball 92, and the number of spray balls 92 can be one or more, for example, two spray balls 92.

[0044] It should be noted that the first liquid inlet branch 9 is used to inject liquid into the raw liquid tank 1, which is usually cleaning liquid and process water, and the cleaning liquid is used for CIP cleaning. The first liquid discharge branch 27 is used to discharge waste liquid in the raw liquid tank 1, such as sewage after cleaning. Before cleaning the raw liquid tank 1, the fourth pneumatic on-off valve 21 needs to be closed.

[0045] In an optional embodiment, as shown in Figure 1 The membrane filtration system further comprises a second liquid inlet branch 25, a second liquid discharge branch 412 and a third liquid discharge branch 79. The connection point of the second liquid inlet branch 25 on the raw liquid outlet pipeline 2 is located on the downstream side of the fourth pneumatic on-off valve 21, and the seventh pneumatic on-off valve 24 is arranged on the second liquid inlet branch 25. The eighth pneumatic on-off valve 413 is arranged on the raw liquid return pipeline 4, and along the material flow direction of the raw liquid return pipeline 4, the connection point of the second liquid discharge branch 412 on the raw liquid return pipeline 4 is located on the upstream side of the eighth pneumatic on-off valve 413, and the second liquid discharge branch 412 is provided with the ninth pneumatic on-off valve 411. The tenth pneumatic on-off valve 77 and the third pressure transmitter 74 are arranged on the clear liquid outlet pipeline 7, and along the material flow direction of the clear liquid outlet pipeline 7, the third pressure transmitter 74 and the tenth pneumatic on-off valve 77 are arranged in sequence, and the connection point of the third liquid discharge branch 79 on the clear liquid outlet pipeline 7 is located between the third pressure transmitter 74 and the tenth pneumatic on-off valve 77, and the third liquid discharge branch 79 is provided with the eleventh pneumatic on-off valve 78. The seventh pneumatic on-off valve 24, the eighth pneumatic on-off valve 413, the ninth pneumatic on-off valve 411, the tenth pneumatic on-off valve 77, the third pressure transmitter 74 and the eleventh pneumatic on-off valve 78 are electrically connected with the control mainboard.

[0046] Specifically, the connection point of the second liquid inlet branch 25 on the raw liquid outlet pipeline 2 is located between the fourth pneumatic on-off valve 21 and the pump body 22. Along the material flow direction of the raw liquid return pipeline 4, the second pressure transmitter 41, the first pneumatic regulating valve 42, the second flow measuring instrument 43, the cooler 44, the first temperature measuring instrument and the eighth pneumatic on-off valve 413 are arranged in sequence, and the connection point of the second liquid discharge branch 412 on the raw liquid return pipeline 4 is located between the eighth pneumatic on-off valve 413 and the first temperature measuring instrument. The second PH value sensor 76 is further arranged on the clear liquid outlet pipeline 7, and along the material flow direction of the clear liquid outlet pipeline 7, the first flow measuring instrument 73, the third pressure transmitter 74, the solid content measuring instrument 75, the second PH value sensor 76 and the tenth pneumatic on-off valve 77 are arranged in sequence, and the connection point of the third liquid discharge branch 79 on the clear liquid outlet pipeline 7 is located between the second PH value sensor 76 and the tenth pneumatic on-off valve 77.

[0047] It should be noted that the seventh pneumatic switch valve 24, the ninth pneumatic switch valve 411 and the eleventh pneumatic switch valve 78 are opened, the tenth pneumatic switch valve 77, the fourth pneumatic switch valve 21 and the eighth pneumatic switch valve 413 are closed, and the membrane module 3 can be cleaned.

[0048] It should be particularly pointed out that, in addition to the normal cleaning process, the system also determines the degree of blockage of the membrane module 3 through the flow value or pressure value of the clear liquid, the membrane circulation pressure value (the pressure value of the first pressure transmitter 23) and other parameters, and when the degree of blockage exceeds the limit, the system can still automatically switch to the cleaning program during filtration, and continue the filtration process after the cleaning is completed.

[0049] In an optional embodiment, as shown in Figure 1 , a manual switch valve is further arranged on the clear liquid discharge pipeline 7, and the manual switch valve is located on the upstream side of the third pressure transmitter 74. Specifically, the manual switch valve is located on the upstream side of the first flow measuring instrument 73.

[0050] The manual switch includes a first manual switch 71 and a second manual switch 72, the first manual switch 71 and the second manual switch 72 are connected in parallel with the membrane module 3, the first manual switch 71 and the second manual switch 72 are located at different positions in the height direction of the membrane module 3, for example, the first manual switch 71 is close to the bottom of the membrane module 3, and the second manual switch 72 is close to the top of the membrane module 3. The first manual switch 71 and the second manual switch 72 are kept in an open state.

[0051] As shown in Figure 2 , the embodiment of the application further provides a running method applied to the membrane filtration system, which comprises the following steps:

[0052] S100, the raw liquid feeding pipeline 5 is opened, so that the material enters the raw liquid tank 1, and the material is circulated between the raw liquid tank 1 and the membrane module 3, and the clear liquid is collected through the clear liquid tank 8.

[0053] S200, the water feeding pipeline 6 is opened according to the liquid level value of the material in the raw liquid tank 1, and the water feeding pipeline 6 is closed according to the solid content value of the clear liquid detected on the clear liquid discharge pipeline 7.

[0054] S300, the membrane filtration system is closed according to the flow value of the clear liquid detected on the clear liquid discharge pipeline 7.

[0055] Specifically, after the feed of fermentation broth through the feed line 5, the fourth pneumatic switch valve 21, the eighth pneumatic switch valve 413 and the tenth pneumatic switch valve 77 are automatically opened to circulate the feed liquid between the feed tank 1 and the membrane module 3. According to the liquid level value of the feed liquid detected by the first liquid level meter 15, the filtration can be paused (the fourth pneumatic switch valve 21, the eighth pneumatic switch valve 413 and the tenth pneumatic switch valve 77 are closed) and the first pneumatic switch valve 61 is automatically opened to start the water replenishment for the feed tank 1. When the liquid level value reaches the target liquid level value, the filtration is continued (the fourth pneumatic switch valve 21, the eighth pneumatic switch valve 413 and the tenth pneumatic switch valve 77 are opened).

[0056] For example, when the liquid level in the feed tank 1 reaches 1 / 4 of the original liquid level, the first pneumatic switch valve 61 is automatically opened to start the water replenishment, and when the liquid level reaches 3 / 4 of the original liquid level, the filtration is continued. Alternatively, when the volume of the feed liquid in the feed tank 1 reaches 1 / 4 of the original volume, the first pneumatic switch valve 61 is automatically opened to start the water replenishment, and when the volume of the water replenishment reaches 1 / 4 of the original volume, the filtration is continued. The volume of the water replenishment can be calculated based on the flow value of the third flow meter 62.

[0057] Subsequently, when the solid content value of the clear liquid detected by the solid content meter 75 is lower than the target solid content value (e.g., 0.5%), the water replenishment is stopped, and when the flow value of the clear liquid detected on the clear liquid discharge line 7 is equal to the target flow value, the filtration is stopped, and the filtration process of the batch of feed liquid is completed.

[0058] In an alternative embodiment, the circulation of the feed liquid between the feed tank 1 and the membrane module 3 comprises:

[0059] The pump body 22 is started, and the operating frequency of the pump body 22 is adjusted to the target operating frequency.

[0060] The opening degree of the first pneumatic regulating valve 42 is adjusted so that the flow value of the second flow meter 43 is equal to the target flow value or the pressure value of the second pressure transmitter 41 is equal to the target pressure value.

[0061] As an example, after the feed of fermentation broth through the feed line 5, the fourth pneumatic switch valve 21, the eighth pneumatic switch valve 413, the tenth pneumatic switch valve 77 and the pump body 22 are automatically opened to circulate the feed liquid between the feed tank 1 and the membrane module 3. Subsequently, the frequency of the pump body 22 is gradually increased to 45 Hz, and the opening degree of the first pneumatic regulating valve 42 is adjusted so that the second pressure transmitter 41 is maintained at 0.25±0.02 Mpa (the pressure value corresponds to a microfiltration membrane) or 0.5±0.05 Mpa (the pressure value corresponds to an ultrafiltration membrane), thereby realizing a constant pressure filtration process. At the same time, the second pneumatic switch valve 46 and the third pneumatic switch valve 49 are opened, the opening degree of the second pneumatic regulating valve 47 is adjusted, and the temperature of the backflow feed liquid is ensured to be lower than 30℃.

[0062] As another example, after the feed of fermentation liquid through feed line 5, the fourth pneumatic on-off valve 21, the eighth pneumatic on-off valve 413 and the tenth pneumatic on-off valve 77 are automatically opened, and the pump body 22 is started to circulate the feed liquid between the feed tank 1 and the membrane module 3. Then the frequency of the pump body 22 is gradually opened to 45 Hz, and the opening of the first pneumatic regulating valve 42 is adjusted to maintain a certain flow value of the second flow meter 43, so as to realize the constant flow filtration process. At this time, the second pressure transmitter 41 starts the monitoring function, and when the system pressure exceeds 0.5 MPa (microfiltration membrane) or 0.8 MPa (ultrafiltration membrane), the system is automatically stopped and an alarm is given. At the same time, the second pneumatic on-off valve 46 and the third pneumatic on-off valve 49 are opened, the opening of the second pneumatic regulating valve 47 is adjusted, and the temperature of the backflow feed liquid is ensured to be lower than 30℃.

[0063] It should be noted that after the completion of the entire filtration process, the sixth pneumatic on-off valve 26 can be opened to discharge the residual feed liquid, and then the CIP cleaning process is carried out. After the completion of the filtration of the feed liquid and the discharge of the feed liquid, the fourth pneumatic on-off valve 21, the eighth pneumatic on-off valve 413 and the tenth pneumatic on-off valve 77 are closed, the fifth pneumatic on-off valve 91 and the sixth pneumatic on-off valve 26 are opened, and the feed tank 1 is cleaned; the seventh pneumatic on-off valve 24, the ninth pneumatic on-off valve 411 and the eleventh pneumatic on-off valve 78 are opened, and the tenth pneumatic on-off valve 77, the fourth pneumatic on-off valve 21 and the eighth pneumatic on-off valve 413 are closed, so that the membrane module 3 can be cleaned. If the filtration is not completed and it is determined that the membrane module 3 is blocked, the fourth pneumatic on-off valve 21, the eighth pneumatic on-off valve 413 and the tenth pneumatic on-off valve 77 are closed, the seventh pneumatic on-off valve 24, the ninth pneumatic on-off valve 411 and the eleventh pneumatic on-off valve 78 are opened, and the cleaning of the membrane module 3 in the middle process is carried out. After the cleaning is completed, the seventh pneumatic on-off valve 24, the ninth pneumatic on-off valve 411 and the eleventh pneumatic on-off valve 78 are closed, the fourth pneumatic on-off valve 21, the eighth pneumatic on-off valve 413 and the tenth pneumatic on-off valve 77 are opened, and the filtration process is continued until completion.

[0064] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that the technical solutions described in the foregoing examples can be modified, or some technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A membrane filtration system, characterized by, The application relates to a membrane filtration system. The membrane filtration system comprises a control mainboard, a water inlet pipeline, a raw liquid feeding pipeline, a raw liquid tank, a raw liquid discharging pipeline, a membrane assembly, a raw liquid return pipeline, a clear liquid discharging pipeline and a clear liquid tank. The water inlet pipeline and the raw liquid feeding pipeline are both communicated with the raw liquid tank, the raw liquid tank is communicated with the membrane assembly through the raw liquid discharging pipeline, the membrane assembly is communicated with the raw liquid tank through the raw liquid return pipeline, and the clear liquid tank is communicated with the membrane assembly through the clear liquid discharging pipeline; wherein the control mainboard is configured to open the water inlet pipeline according to the liquid level value of the material in the raw liquid tank, to close the water inlet pipeline according to the solid content value of the clear liquid detected on the clear liquid discharging pipeline, and to close the membrane filtration system according to the flow value of the clear liquid detected on the clear liquid discharging pipeline.

2. The membrane filtration system of claim 1, wherein, The water inlet pipeline is provided with a first pneumatic on-off valve, the raw liquid tank is provided with a first liquid level measuring instrument, the clear liquid discharging pipeline is provided with a solid content measuring instrument and a first flow measuring instrument, and the first pneumatic on-off valve, the first liquid level measuring instrument, the solid content measuring instrument and the first flow measuring instrument are all electrically connected with the control mainboard.

3. The membrane filtration system of claim 1, wherein, The raw liquid discharging pipeline is provided with a pump body and a first pressure transmitter, and the pump body and the first pressure transmitter are sequentially arranged along the material flow direction of the raw liquid discharging pipeline; the raw liquid return pipeline is provided with a second pressure transmitter, a first pneumatic regulating valve and a second flow measuring instrument, and the second pressure transmitter, the first pneumatic regulating valve and the second flow measuring instrument are sequentially arranged along the material flow direction of the raw liquid return pipeline; wherein the pump body, the first pressure transmitter, the second pressure transmitter, the first pneumatic regulating valve and the second flow measuring instrument are all electrically connected with the control mainboard.

4. The membrane filtration system of claim 1, wherein, The raw liquid return pipeline is provided with a heat exchange pipeline and a first temperature measuring instrument, and the heat exchange pipeline and the first temperature measuring instrument are sequentially arranged along the material flow direction of the raw liquid return pipeline; wherein the control mainboard is further configured to control the heat exchange pipeline to adjust the temperature of the material flowing through the raw liquid return pipeline, so that the temperature value of the first temperature measuring instrument is equal to a target temperature value.

5. The membrane filtration system of claim 4, wherein, The heat exchange pipeline comprises a cooler, a first cooling liquid branch and a second cooling liquid branch, the cooler has a material channel and a cooling liquid channel, the first cooling liquid branch and the second cooling liquid branch are both communicated with the cooling liquid channel; wherein the first cooling liquid branch is provided with a second pneumatic on-off valve and a second pneumatic regulating valve, and the second pneumatic on-off valve and the second pneumatic regulating valve are sequentially arranged along the material flow direction of the first cooling liquid branch; the second cooling liquid branch is provided with a third pneumatic on-off valve; and the second pneumatic on-off valve, the second pneumatic regulating valve and the third pneumatic on-off valve are all electrically connected with the control mainboard.

6. The membrane filtration system of claim 1, wherein, The membrane filtration system further comprises a first liquid inlet branch and a first blowdown branch, the first liquid inlet branch is communicated with the raw liquid tank, the raw liquid outlet pipeline is further provided with a fourth pneumatic switch valve; along the material flow direction of the raw liquid return pipeline, the connecting point of the first blowdown branch on the raw liquid outlet pipeline is located on the upstream side of the fourth pneumatic switch valve; the first liquid inlet branch is provided with a fifth pneumatic switch valve, the first blowdown branch is provided with a sixth pneumatic switch valve, and the fourth pneumatic switch valve, the fifth pneumatic switch valve and the sixth pneumatic switch valve are electrically connected with the control mainboard.

7. The membrane filtration system of claim 6, wherein, The membrane filtration system further comprises a second liquid inlet branch, a second blowdown branch and a third blowdown branch, the connecting point of the second liquid inlet branch on the raw liquid outlet pipeline is located on the downstream side of the fourth pneumatic switch valve, and the second liquid inlet branch is provided with a seventh pneumatic switch valve; the raw liquid return pipeline is provided with an eighth pneumatic switch valve, along the material flow direction of the raw liquid return pipeline, the connecting point of the second blowdown branch on the raw liquid return pipeline is located on the upstream side of the eighth pneumatic switch valve, and the second blowdown branch is provided with a ninth pneumatic switch valve; the clear liquid outlet pipeline is provided with a tenth pneumatic switch valve and a third pressure transmitter, along the material flow direction of the clear liquid outlet pipeline, the third pressure transmitter and the tenth pneumatic switch valve are sequentially arranged, the connecting point of the third blowdown branch on the clear liquid outlet pipeline is located between the third pressure transmitter and the tenth pneumatic switch valve, and the third blowdown branch is provided with an eleventh pneumatic switch valve; the seventh pneumatic switch valve, the eighth pneumatic switch valve, the ninth pneumatic switch valve, the tenth pneumatic switch valve, the third pressure transmitter and the eleventh pneumatic switch valve are electrically connected with the control mainboard.

8. The membrane filtration system of claim 7, wherein, The clear liquid outlet pipeline is further provided with a manual switch valve, and the manual switch valve is located on the upstream side of the third pressure transmitter.

9. A method for operating a membrane filtration system according to any one of claims 1 to 8, characterized in that The method comprises the following steps: opening the raw liquid inlet pipeline to make the material enter the raw liquid tank and circulate between the raw liquid tank and the membrane assembly, and collect the clear liquid through the clear liquid tank; opening the water inlet pipeline according to the liquid level value of the material in the raw liquid tank, and closing the water inlet pipeline according to the solid content value of the clear liquid detected on the clear liquid outlet pipeline; closing the membrane filtration system according to the flow value of the clear liquid detected on the clear liquid outlet pipeline.

10. The method of operating a membrane filtration system of claim 9, wherein, The step of making the material circulate between the raw liquid tank and the membrane assembly comprises the following steps: opening the pump body and adjusting the working frequency of the pump body to a target working frequency; adjusting the opening degree of the first pneumatic regulating valve to make the flow value of the second flow measuring instrument equal to a target flow value or the pressure value of the second pressure transmitter equal to a target pressure value.

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