Membrane filtration system and method for operating same

Abstract

The invention relates to the technical field of biological engineering, and provides a membrane filtration system and an operation method thereof.The membrane filtration system comprises a control mainboard, a water inlet pipeline, a stock solution feeding pipeline, a stock solution tank, a stock solution discharging pipeline, a membrane assembly, a stock solution backflow pipeline, a clear solution discharging pipeline and a clear solution tank; the water inlet pipeline and the stock solution feeding pipeline are both communicated with the stock solution tank, the stock solution tank is communicated with the membrane assembly through the stock solution discharging pipeline, the membrane assembly is communicated with the stock solution tank through the stock solution backflow pipeline, and the clear solution tank is communicated with the membrane assembly through the clear solution discharging pipeline; the control main board is configured to open the water inlet pipeline according to the liquid level value of the material in the stock solution 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. Therefore, the material state in operation can be automatically monitored and judged, and corresponding adjustment is automatically completed, so that 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, an original liquid feeding pipeline, an original liquid tank, an original liquid discharging pipeline, a membrane assembly, an original liquid return pipeline, a clear liquid discharging pipeline and a clear liquid tank. The water inlet pipeline and the original liquid feeding pipeline are both in communication with the original liquid tank, the original liquid tank is in communication with the membrane assembly through the original liquid discharging pipeline, the membrane assembly is in communication with the original liquid tank through the original 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 original 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.

[0005] 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 original 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.

[0006] According to a membrane filtration system provided by the present invention, the feed liquid outlet pipeline is provided with a pump body and a first pressure transmitter, which are arranged sequentially along the material flow direction of the feed liquid outlet pipeline; the feed liquid return pipeline is provided with a second pressure transmitter, a first pneumatic regulating valve and a second flow meter, which are arranged sequentially along the material flow direction of the feed liquid return pipeline; wherein, the pump body, the first pressure transmitter, the second pressure transmitter, the first pneumatic regulating valve and the second flow meter are all electrically connected to the control main board.

[0007] According to a membrane filtration system provided by the present invention, the feed 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 arranged sequentially along the material flow direction of the feed liquid return pipeline; wherein, the control main board is further configured to control the heat exchange pipeline to adjust the temperature of the material flowing through the feed liquid return pipeline, so that the temperature value of the first temperature measuring instrument is equal to the target temperature value.

[0008] According to a membrane filtration system provided by the present invention, the heat exchange pipeline includes a cooler, a first coolant branch, and a second coolant branch. The cooler has a material channel and a coolant channel. The material channel is connected to the raw liquid return pipeline. The first coolant branch and the second coolant branch are both connected to the coolant channel. The first coolant branch is equipped with a second pneumatic switching valve and a second pneumatic regulating valve, which are sequentially arranged along the material flow direction of the first coolant branch. The second coolant branch is equipped with a third pneumatic switching valve. The second pneumatic switching valve, the second pneumatic regulating valve, and the third pneumatic switching valve are all electrically connected to the control main board.

[0009] According to a membrane filtration system provided by the present invention, the membrane filtration system further includes a first inlet branch and a first drain branch. The first inlet branch is connected to the raw liquid tank, and the raw liquid outlet pipeline is also provided with a fourth pneumatic switch valve. Along the material flow direction of the raw liquid return pipeline, the connection point of the first drain branch on the raw liquid outlet pipeline is located upstream of the fourth pneumatic switch valve. The first inlet branch is provided with a fifth pneumatic switch valve, and the first drain branch is provided with a sixth pneumatic switch valve. The fourth, fifth, and sixth pneumatic switch valves are all electrically connected to the control main board.

[0010] According to a membrane filtration system provided by the present invention, the membrane filtration system further includes a second inlet branch, a second drain branch, and a third drain branch. The connection point of the second inlet branch on the feed liquid outlet pipeline is located downstream of the fourth pneumatic switch valve, and a seventh pneumatic switch valve is provided on the second inlet branch. An eighth pneumatic switch valve is provided on the feed liquid return pipeline along the material flow direction of the feed liquid return pipeline. The connection point of the second drain branch on the feed liquid return pipeline is located upstream of the eighth pneumatic switch valve, and a ninth pneumatic switch valve is provided on the second drain branch. The clarified liquid outlet... A tenth pneumatic switch valve and a third pressure transmitter are installed on the material pipeline. The third pressure transmitter and the tenth pneumatic switch valve are sequentially arranged along the material flow direction of the clear liquid discharge pipeline. The connection point of the third sewage branch on the clear liquid discharge pipeline is located between the third pressure transmitter and the tenth pneumatic switch valve. An eleventh pneumatic switch valve is installed on the third sewage branch. The seventh, eighth, ninth, tenth, third pressure transmitter, and eleventh pneumatic switch valves are all electrically connected to the control main board.

[0011] According to a membrane filtration system provided by the present invention, a manual switching valve is further provided on the clarified liquid discharge pipeline, and the manual switching valve is located upstream of the third pressure transmitter.

[0012] The present invention also provides a method for operating a membrane filtration system, comprising: The feed line is opened to allow the material to enter the feed tank and circulate between the feed tank and the membrane module, and the clarified liquid is collected through the clarified liquid tank. The water inlet pipe is opened according to the liquid level of the material in the raw liquid tank, and the water inlet pipe is closed according to the solid content of the clear liquid detected on the clear liquid outlet pipe. The membrane filtration system is shut down based on the flow rate of the clarified liquid detected on the clarified liquid discharge line.

[0013] According to a method for operating a membrane filtration system provided by the present invention, the step of circulating the material between the feed tank and the membrane module includes: Turn on the pump and adjust its operating frequency to the target operating frequency; Adjust the opening of the first pneumatic regulating valve so that the flow rate of the second flow meter is equal to the target flow rate or the pressure value of the second pressure transmitter is equal to the target pressure value.

[0014] The membrane filtration system and its operating method provided by this invention involve opening the feed line to introduce the feed solution to be filtered into the feed tank. Once the feed solution in the tank reaches a certain volume, the feed line is closed, and the filtration process begins. Simultaneously, the liquid level in the feed tank is monitored in real time and transmitted to the control mainboard. The control mainboard, according to a preset program, determines whether the liquid level in the feed tank has reached the set value for opening the water inlet line. When the set value is reached, the control mainboard issues a command to open the water inlet line and add water to the feed tank. After adding a certain amount of water, the feed outlet line, feed return line, and clarified liquid outlet line are opened. The material in the feed tank enters the membrane module for further filtration through the feed outlet line. Throughout the filtration process, the solids content of the clarified liquid in the clarified liquid outlet line is monitored in real time and transmitted to the control mainboard. The flow rate of the clarified liquid in the clarified liquid outlet line is also monitored in real time and transmitted to the control mainboard. The control board compares the received solids content of the clarified liquid with a preset solids content threshold for closing the inlet water pipe. When the detected solids content reaches the preset threshold, the control board issues a command to close the inlet water pipe, stopping the addition of water to the raw liquid tank. The control board continues to monitor the flow rate of the clarified liquid in the clarified liquid outlet pipe and compares it with a preset flow rate threshold for shutting off the membrane filtration system. When the detected clarified liquid flow rate is lower than the preset threshold, the control board issues a command to stop the operation of the membrane filtration system. In this way, the system can automatically monitor and determine the material status during operation, automatically make corresponding adjustments, and thus achieve automatic control of the microbial fermentation broth separation process. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the membrane filtration system provided by the present invention.

[0017] Figure 2 This is a flowchart of the operation method of the membrane filtration system provided by the present invention.

[0018] Figure label: 1. Raw material tank; 11. Containing space; 12. Agitator; 13. First pH sensor; 14. Second temperature measuring instrument; 15. First liquid level measuring instrument; 2. Raw material discharge pipeline; 21. Fourth pneumatic switch valve; 22. Pump body; 23. First pressure transmitter; 24. Seventh pneumatic switch valve; 25. Second inlet branch; 26. Sixth pneumatic switch valve; 27. First drain branch; 3. Membrane module; 4. Raw material return pipeline; 41. Second pressure transmitter; 42. First pneumatic regulating valve; 43. Second flow measuring instrument; 44. Cooler; 45. First coolant branch; 46. Second pneumatic switch valve; 47. Second pneumatic regulating valve; 48. Second coolant branch; 49. Third pneumatic switch valve; 4 10. First temperature measuring instrument; 411. Ninth pneumatic switch valve; 412. Second sewage branch; 413. Eighth pneumatic switch valve; 5. Raw material feed pipeline; 51. Twelfth pneumatic switch valve; 6. Water inlet pipeline; 61. First pneumatic switch valve; 62. Third flow measuring instrument; 7. Clear liquid 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 switch valve; 78. Eleventh pneumatic switch valve; 79. Third sewage branch; 8. Clear liquid tank; 81. Second liquid level measuring instrument; 9. First liquid inlet branch; 91. Fifth pneumatic switch valve; 92. Spray ball. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0020] like Figure 1As shown, the membrane filtration system of this invention can be used to separate microbial cells and macromolecules in microbial fermentation broth. The membrane filtration system includes: a control main board, an inlet water pipe 6, a raw liquid feed pipe 5, a raw liquid tank 1, a raw liquid discharge pipe 2, a membrane module 3, a raw liquid reflux pipe 4, a clarified liquid discharge pipe 7, and a clarified liquid tank 8. The clarified liquid tank 8 may be equipped with a second level measuring instrument 81, which is used to detect the level of the clarified liquid in the clarified liquid tank 8. Both the inlet water pipe 6 and the raw liquid feed pipe 5 are connected to the raw liquid tank 1, and the raw liquid tank 1 discharges raw liquid. Pipeline 2 is connected to membrane module 3, membrane module 3 is connected to raw liquid tank 1 through raw liquid return pipeline 4, and clear liquid tank 8 is connected to membrane module 3 through clear liquid discharge pipeline 7; wherein, the control board is configured to open water inlet pipeline 6 according to the liquid level value of the material in raw liquid tank 1, close water inlet pipeline 6 according to the solid content value of clear liquid detected on clear liquid discharge pipeline 7, and close membrane filtration system according to the flow rate value of clear liquid detected on clear liquid discharge pipeline 7.

[0021] It should be noted that membrane module 3 can be a microfiltration membrane or an ultrafiltration membrane. Microfiltration membranes are generally ceramic membranes or hollow fiber membranes, while ultrafiltration membranes are generally spiral wound membranes or hollow fiber membranes. Microfiltration membranes are used for cell filtration in fermentation broth, while ultrafiltration membranes are used for filtration of the clarified liquid after microfiltration, removing large molecules such as proteins, nucleic acids, and endotoxins.

[0022] Specifically, the inlet water pipe 6 and the feed liquid pipe 5 are sealed to their respective interfaces in the feed liquid tank 1 to ensure no leakage at the connection. The feed liquid tank 1 is tightly connected to the inlet of the membrane module 3 via the feed liquid outlet pipe 2, and the return port of the membrane module 3 is connected to the feed liquid tank 1 via the feed liquid return pipe 4, forming a circulation loop for the feed liquid. The clarified liquid tank 8 is connected to the clarified liquid outlet of the membrane module 3 via the clarified liquid outlet pipe 7 to collect the filtered clarified liquid.

[0023] In practical applications, the feed line 5 is opened to introduce the raw liquid to be filtered into the feed tank 1. Once the amount of raw liquid in the feed tank 1 reaches a certain level, the feed line 5 is closed, and the filtration process begins. Simultaneously, the liquid level in the feed tank 1 is monitored in real time and transmitted to the control board. The control board, based on a preset program, determines whether the liquid level in the feed tank 1 has reached the set value for opening the water inlet line 6. When the set value is reached, the control board issues a command to open the water inlet line 6, adding water to the feed tank 1. After adding a certain amount of water to the feed tank 1, the feed outlet line 2, the feed return line 4, and the clarified liquid outlet line 7 are opened. The material in the feed tank 1 then enters the membrane module 3 through the feed outlet line 2 for further filtration.

[0024] It is particularly important to note that throughout the filtration process, the solids content of the clarified liquid in the clarified liquid discharge pipe 7 is monitored in real time and transmitted to the control mainboard. Similarly, the flow rate of the clarified liquid in the clarified liquid discharge pipe 7 is monitored in real time and transmitted to the control mainboard. The control mainboard compares the received clarified liquid solids content with a preset solids content threshold for shutting off the inlet water pipe 6. When the detected clarified liquid solids content reaches the preset threshold, the control mainboard issues a command to shut off the inlet water pipe 6, stopping the addition of water to the raw liquid tank 1. The control mainboard continues to monitor the clarified liquid flow rate in the clarified liquid discharge pipe 7 and compares it with a preset flow rate threshold for shutting off the membrane filtration system. When the detected clarified liquid flow rate is lower than the preset threshold, the control mainboard issues a command to stop the operation of the membrane filtration system. In this way, the material status during operation can be automatically monitored and judged, and corresponding adjustments can be automatically made, thereby achieving automatic control of the microbial fermentation broth separation process.

[0025] As an example, such as Figure 1 As shown, the inlet pipe 6 is equipped with a first pneumatic switch valve 61, the raw liquid tank 1 is equipped with a first liquid level measuring instrument 15, and the clear liquid outlet pipe 7 is equipped with a solid content measuring instrument 75 and a first flow measuring instrument 73. The first pneumatic switch valve 61, the first liquid level measuring instrument 15, the solid content measuring instrument 75, and the first flow measuring instrument 73 are all electrically connected to the control main board. For example, there can be multiple first liquid level measuring instruments 15, which are arranged sequentially along the height direction of the raw liquid tank 1.

[0026] The feed line 5 is equipped with a twelfth pneumatic switch valve 51, and the water inlet line 6 is equipped with a third flow meter 62. The third flow meter 62 and the first pneumatic switch valve 61 are sequentially arranged along the material flow direction of the water inlet line 6. The feed tank 1 is also equipped with a first pH sensor 13 and a second temperature meter 14 to detect the pH and temperature of the material in the feed tank 1. Furthermore, the feed tank 1 has a containment space 11, within which a stirrer 12 is installed to ensure that the material in the containment space 11 is constantly mixed.

[0027] In optional embodiments, such as Figure 1 As shown, the raw liquid discharge pipeline 2 is equipped with a pump body 22 and a first pressure transmitter 23, which are arranged sequentially along the material flow direction of the raw liquid discharge pipeline 2; the raw liquid return pipeline 4 is equipped with a second pressure transmitter 41, a first pneumatic regulating valve 42, and a second flow meter 43, which are arranged sequentially 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 meter 43 are all electrically connected to the control main board.

[0028] 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 the data back to the control mainboard. The control mainboard determines whether the current pressure is normal based on the preset pressure range. If the pressure is too high, there may be problems such as excessive output from the pump body 22 or blockage of the membrane module 3; if the pressure is too low, it may be due to a malfunction in the pump body 22 or pipeline leakage. When the pressure exceeds the preset range, the control mainboard will issue an alarm and take corresponding adjustment measures. The pump body 22 can be a variable frequency pump.

[0029] Understandably, the second pressure transmitter 41 monitors the pressure in the raw liquid return line 4 in real time, and the second flow meter 43 monitors the flow rate in the raw liquid return line 4 in real time, transmitting the data to the control main board. If the pressure is too high or the flow rate is too high, the control main board will send a command to the first pneumatic regulating valve 42 to reduce the valve opening, thereby reducing the flow rate and pressure in the raw liquid return line 4; conversely, if the pressure is too low or the flow rate is too low, the valve opening will be increased, thereby increasing the flow rate and pressure. Through this dynamic adjustment, the pressure and flow rate in the raw liquid return line 4 are always kept within a suitable range, improving the efficiency and stability of membrane filtration. In other words, the membrane filtration system can be configured to operate in either constant pressure or constant flow mode.

[0030] To achieve precise temperature control of the material flowing through the raw liquid return pipeline 4, in an optional embodiment, such as Figure 1 As shown, the raw liquid return pipeline 4 is equipped with a heat exchange pipeline and a first temperature measuring instrument 410. The heat exchange pipeline and the first temperature measuring instrument 410 are arranged sequentially along the material flow direction of the raw liquid return pipeline 4. The control board is also 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 equals the target temperature value. Specifically, along the material flow direction of the raw liquid return pipeline 4, the heat exchange pipeline is located downstream of the second flow measuring instrument 43.

[0031] As an example, the heat exchange pipeline includes a cooler 44, a first coolant branch 45, and a second coolant branch 48. The cooler 44 has a material channel and a coolant channel. The material channel is connected to the raw liquid return pipeline 4. The first coolant branch 45 and the second coolant branch 48 are both connected to the coolant channel. The first coolant branch 45 is equipped with a second pneumatic switch valve 46 and a second pneumatic regulating valve 47. The second pneumatic switch valve 46 and the second pneumatic regulating valve 47 are arranged sequentially along the material flow direction of the first coolant branch 45. The second coolant branch 48 is equipped with a third pneumatic switch valve 49. The second pneumatic switch valve 46, the second pneumatic regulating valve 47, and the third pneumatic switch valve 49 are all electrically connected to the control main board.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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.

[0037] It should be noted that the first inlet branch 9 is used to inject liquid into the raw material tank 1, typically cleaning fluid and process water. The cleaning fluid is used for CIP cleaning. The first drain branch 27 is used to discharge waste liquid, such as wastewater after cleaning, from the raw material tank 1. It is important to note that the fourth pneumatic switch valve 21 must be closed before cleaning the raw material tank 1.

[0038] In optional embodiments, such as Figure 1 As shown, the membrane filtration system also includes a second inlet branch 25, a second drain branch 412, and a third drain branch 79. The connection point of the second inlet branch 25 on the raw liquid discharge pipeline 2 is located downstream of the fourth pneumatic switch valve 21, and a seventh pneumatic switch valve 24 is installed on the second inlet branch 25. An eighth pneumatic switch valve 413 is installed on the raw liquid return pipeline 4. Along the material flow direction of the raw liquid return pipeline 4, the connection point of the second drain branch 412 on the raw liquid return pipeline 4 is located upstream of the eighth pneumatic switch valve 413, and a ninth pneumatic switch valve 411 is installed on the second drain branch 412. The clear liquid discharge pipeline 79... The system is equipped with a tenth pneumatic switch valve 77 and a third pressure transmitter 74. Along the material flow direction of the clear liquid discharge pipeline 7, the third pressure transmitter 74 and the tenth pneumatic switch valve 77 are arranged in sequence. The connection point of the third sewage branch 79 on the clear liquid discharge pipeline 7 is located between the third pressure transmitter 74 and the tenth pneumatic switch valve 77. The third sewage branch 79 is equipped with an eleventh pneumatic switch valve 78. The seventh pneumatic switch valve 24, the eighth pneumatic switch valve 413, the ninth pneumatic switch valve 411, the tenth pneumatic switch valve 77, the third pressure transmitter 74, and the eleventh pneumatic switch valve 78 are all electrically connected to the control main board.

[0039] Specifically, the connection point of the second inlet branch 25 on the raw liquid outlet pipeline 2 is located between the fourth pneumatic switch 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 meter 43, the cooler 44, the first temperature meter, and the eighth pneumatic switch valve 413 are sequentially arranged. The connection point of the second drain branch 412 on the raw liquid return pipeline 4 is located between the eighth pneumatic switch valve 413 and the first temperature meter. A second pH sensor 76 is also installed on the clear liquid outlet pipeline 7. Along the material flow direction of the clear liquid outlet pipeline 7, the first flow meter 73, the third pressure transmitter 74, the solids content meter 75, the second pH sensor 76, and the tenth pneumatic switch valve 77 are sequentially arranged. The connection point of the third drain branch 79 on the clear liquid outlet pipeline 7 is located between the second pH sensor 76 and the tenth pneumatic switch valve 77.

[0040] It should be noted that opening the seventh pneumatic switch valve 24, the ninth pneumatic switch valve 411, and the eleventh pneumatic switch valve 78, and closing the tenth pneumatic switch valve 77, the fourth pneumatic switch valve 21, and the eighth pneumatic switch valve 413, can clean the membrane module 3.

[0041] It is particularly important to note that, in addition to the normal cleaning process, the system also determines the degree of clogging of the membrane module 3 by parameters such as the flow rate or pressure value of the cleaning liquid and the membrane circulation pressure value (pressure value of the first pressure transmitter 23). When the degree of clogging exceeds the limit, the system can still automatically switch to the cleaning program during filtration, and continue the filtration process after cleaning is completed.

[0042] In optional embodiments, such as Figure 1 As shown, a manual switch valve is also installed on the clear liquid discharge pipeline 7, which is located upstream of the third pressure transmitter 74. Specifically, the manual switch valve is located upstream of the first flow meter 73.

[0043] The manual switches include a first manual switch 71 and a second manual switch 72, which are connected in parallel with the membrane assembly 3. The first and second manual switches 71 and 72 are located at different positions along the height of the membrane assembly 3; for example, the first manual switch 71 is near the bottom of the membrane assembly 3, and the second manual switch 72 is near the top of the membrane assembly 3. Both the first and second manual switches 71 and 72 are normally open.

[0044] like Figure 2 As shown, this embodiment of the invention also provides an operating method for a membrane filtration system, comprising: S100, open the feed line 5 to allow the material to enter the feed tank 1 and circulate between the feed tank 1 and the membrane module 3, and collect the clarified liquid through the clarified liquid tank 8.

[0045] S200, the water inlet pipe 6 is opened according to the liquid level value of the material in the raw liquid tank 1, and the water inlet pipe 6 is closed according to the solid content value of the clear liquid detected on the clear liquid outlet pipe 7.

[0046] S300, shut down the membrane filtration system based on the flow rate of the clarified liquid detected on the clarified liquid discharge line 7.

[0047] Specifically, after the fermentation broth is fed into the raw material tank 1 via the raw material feed pipeline 5, the fourth pneumatic switch valve 21, the eighth pneumatic switch valve 413, and the tenth pneumatic switch valve 77 are automatically opened, allowing the broth to circulate between the raw material tank 1 and the membrane module 3. Based on the material level detected by the first level measuring instrument 15 in the raw material tank 1, filtration can be paused (by closing the fourth pneumatic switch valve 21, the eighth pneumatic switch valve 413, and the tenth pneumatic switch valve 77), and the first pneumatic switch valve 61 is automatically opened to begin replenishing water to the raw material tank 1. When the liquid level reaches the target level, filtration resumes (by opening the fourth pneumatic switch valve 21, the eighth pneumatic switch valve 413, and the tenth pneumatic switch valve 77).

[0048] For example, when the liquid level in the raw liquid tank 1 reaches 1 / 4 of the original liquid level, the first pneumatic switch valve 61 is automatically opened to start water replenishment. When the liquid level in the raw liquid tank 1 reaches 3 / 4 of the original liquid level, filtration continues. Alternatively, when the volume of the liquid in the raw liquid tank 1 reaches 1 / 4 of the original volume, the first pneumatic switch valve 61 is automatically opened to start water replenishment. When the replenished water volume reaches 1 / 4 of the original volume, filtration continues. The replenished water volume can be calculated from the flow rate value of the third flow meter 62.

[0049] Subsequently, when the solid content of the clear liquid detected by the solid content measuring instrument 75 is lower than the target solid content (e.g., 0.5%), water replenishment is stopped, and filtration is stopped when the flow rate of the clear liquid detected on the clear liquid discharge pipeline 7 is equal to the target flow rate, thus completing the filtration process for this batch of liquid.

[0050] In an optional embodiment, circulating the material between the feed tank 1 and the membrane module 3 includes: Turn on pump body 22 and adjust the operating frequency of pump body 22 to the target operating frequency; Adjust the opening of the first pneumatic regulating valve 42 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.

[0051] As an example, after the fermentation broth is fed into the raw material tank 1 via the raw material feed pipeline 5, the fourth pneumatic switch valve 21, the eighth pneumatic switch valve 413, and the tenth pneumatic switch valve 77 are automatically opened, and the pump body 22 is started, causing the feed liquid to circulate between the raw material tank 1 and the membrane module 3. Then, the pump body 22 frequency is gradually increased to 45Hz, and the opening of the first pneumatic regulating valve 42 is adjusted to maintain the second pressure transmitter 41 at 0.25±0.02MPa (corresponding to the microfiltration membrane) or 0.5±0.05MPa (corresponding to the ultrafiltration membrane), achieving a constant pressure filtration process. Simultaneously, the second pneumatic switch valve 46 and the third pneumatic switch valve 49 are opened, and the opening of the second pneumatic regulating valve 47 is adjusted to ensure that the temperature of the reflux feed liquid is below 30℃.

[0052] As another example, after the fermentation broth is fed into the raw material tank 1 via the raw material feed pipeline 5, the fourth pneumatic switch valve 21, the eighth pneumatic switch valve 413, and the tenth pneumatic switch valve 77 are automatically opened, and the pump body 22 is started, causing the broth to circulate between the raw material tank 1 and the membrane module 3. Then, the pump body 22 frequency is gradually increased to 45Hz, and the opening of the first pneumatic regulating valve 42 is adjusted to maintain a certain flow rate in the second flow meter 43, achieving a constant flow filtration process. At this time, the second pressure transmitter 41 activates its monitoring function; when the system pressure exceeds 0.5 MPa (microfiltration membrane) or 0.8 MPa (ultrafiltration membrane), it automatically shuts down and alarms. Simultaneously, the second pneumatic switch valve 46 and the third pneumatic switch valve 49 are opened, and the opening of the second pneumatic regulating valve 47 is adjusted to ensure that the temperature of the reflux broth is below 30°C.

[0053] It should be noted that after the entire filtration process is completed, the sixth pneumatic switch valve 26 can be opened to drain the residual liquid before proceeding with the CIP cleaning process. Thus, after the liquid filtration is complete and drained, the fourth pneumatic switch valve 21, the eighth pneumatic switch valve 413, and the tenth pneumatic switch valve 77 are closed, and the fifth pneumatic switch valve 91 and the sixth pneumatic switch valve 26 are opened to clean the feed tank 1; the seventh pneumatic switch valve 24, the ninth pneumatic switch valve 411, and the eleventh pneumatic switch valve 78 are opened, and the tenth pneumatic switch valve 77, the fourth pneumatic switch valve 21, and the eighth pneumatic switch valve 413 are closed to clean the membrane module 3. If filtration is not yet complete and membrane module 3 is found to be clogged, close the fourth pneumatic switch valve 21, the eighth pneumatic switch valve 413, and the tenth pneumatic switch valve 77, and open the seventh pneumatic switch valve 24, the ninth pneumatic switch valve 411, and the eleventh pneumatic switch valve 78 to perform intermediate cleaning of membrane module 3. After cleaning, close the seventh pneumatic switch valve 24, the ninth pneumatic switch valve 411, and the eleventh pneumatic switch valve 78, and open the fourth pneumatic switch valve 21, the eighth pneumatic switch valve 413, and the tenth pneumatic switch valve 77 to continue the filtration process until it is complete.

[0054] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

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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