A membrane filtration device for citric acid production

Abstract

The utility model provides a membrane filtration device for citric acid production, including the bottom plate, the one side of bottom plate top is provided with first filter box, and the central position department of first filter box is inserted with the plate and frame type nanofiltration membrane, the other side of bottom plate top is provided with second filter box, and the central position department of second filter box is inserted with the plate and frame type reverse osmosis RO membrane. Compared with prior art, the utility model has the beneficial effects as follows: first reflux pipe and second reflux pipe cooperate with booster pump, the wastewater that is not filtered completely is not directly discharged, but is parallel to the membrane surface backflow filtration again with certain flow rate, this cross flow filtration mode makes fluid form turbulent flow on the membrane surface, reduces concentration polarization phenomenon, delays the impurity accumulation on the membrane surface and forms filter cake layer, utilizes cross flow filtration principle, greatly improves the mass transfer effect in the membrane filtration process, effectively delays the membrane pollution process, prolongs the cleaning cycle and service life of membrane assembly, reduces the operation and maintenance cost of equipment.

Description

Technical Field

[0001] This utility model is a membrane filtration device for citric acid production, belonging to the field of membrane filtration devices. Background Technology

[0002] Citric acid production generates a large amount of wastewater, which contains not only high concentrations of organic matter and suspended solids, but also a certain amount of salt. With the rise of membrane filtration technology, it has gradually become an important means of treating citric acid wastewater due to its advantages such as high separation efficiency, low energy consumption, and simple operation. In particular, nanofiltration membranes and reverse osmosis membranes have performed well in removing organic matter and salt, making it possible to utilize wastewater resources. Currently, traditional membrane filtration devices used for citric acid wastewater treatment mainly have plate and frame, spiral wound, and hollow fiber structures. Plate and frame membrane filtration devices are composed of multiple membrane modules stacked together. Each membrane module includes a membrane sheet, a support plate, and a guide plate. Wastewater flows between the membrane sheets to complete filtration.

[0003] During filtration, impurities such as particles and colloids trapped by the membrane gradually deposit on the membrane surface. Traditional devices lack sufficient shear force on the membrane surface to disperse impurities, which continuously accumulate and connect with each other, eventually forming a filter cake layer. This filter cake layer greatly increases the resistance of fluid passing through the membrane, further hindering solvent permeation and reducing filtration efficiency. Therefore, it is necessary to design a membrane filtration device for citric acid production. Utility Model Content

[0004] In view of the shortcomings of the existing technology, the purpose of this utility model is to provide a membrane filtration device for citric acid production, so as to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model is implemented through the following technical solution: a membrane filtration device for citric acid production, comprising a base plate, a first filter box disposed on one side of the top of the base plate, and a plate-and-frame nanofiltration membrane inserted at the center of the first filter box; a second filter box disposed on the other side of the top of the base plate; a first reflux pipe disposed at the center of both ends of the first filter box, with the outlet end of the first reflux pipe connected to the top of the first filter box; a second reflux pipe disposed at the center of both ends of the second filter box, with the outlet end of the second reflux pipe connected to the top of the second filter box; a booster pump disposed on both the first and second reflux pipes; a liquid delivery cylinder installed on the top of the first filter box, and a filter port opened at the bottom of the liquid delivery cylinder near the first filter box, with a primary filter screen disposed inside the filter port.

[0006] Furthermore, a water pump is installed at the center of the top of the base plate, and the input end of the water pump is connected to the bottom of the first filter box. A spray pipe is installed at the center of the top of the second filter box, and spray nozzles are evenly arranged at the bottom of the spray pipe. A three-way valve is installed at the output end of the water pump, and the two liquid outlets of the three-way valve are respectively connected to a liquid guide pipe and a liquid outlet pipe. The liquid guide pipe is connected to the spray pipe.

[0007] Furthermore, a lower groove is provided at the center of the top of the first filter box, and the shape of the lower groove matches the outer shape of the infusion cylinder. Rubber sealing rings are provided on both semi-circular groove walls of the lower groove.

[0008] Furthermore, a clean water outlet is provided at the bottom of one end of the second filter box, and a plate and frame reverse osmosis (RO) membrane is inserted into the center of the second filter box.

[0009] Furthermore, an inlet is provided on the top of the infusion cylinder near the first filter box, and a slag discharge port is provided on the bottom of the infusion cylinder away from the first filter box. Connecting plates are provided at both ends of the infusion cylinder near the lower groove, and the connecting plates are connected to the top of the first filter box by bolts.

[0010] Furthermore, the infusion cylinder is equipped with a conveying screw inside, and a cleaning component is installed on the conveying screw. A drive motor is provided on one side of the infusion cylinder, and the output end of the drive motor is connected to the conveying screw.

[0011] Furthermore, the cleaning assembly consists of a connecting plate, two spring buffer columns, a silicone scraper, and two mounting hoops. The two mounting hoops are respectively fixed to both ends of the delivery screw, and spring buffer columns extend vertically from the mounting hoops. The tops of the two spring buffer columns are connected by the connecting plate, and a silicone scraper is embedded on the outer side of the connecting plate. The silicone scraper is in contact with the inner wall of the infusion cylinder.

[0012] The beneficial effects of this utility model are:

[0013] 1. The first and second return pipes, in conjunction with a booster pump, ensure that unfiltered wastewater is not directly discharged but instead flows back to the membrane surface at a certain velocity for further filtration. This cross-flow filtration method creates turbulence on the membrane surface, reducing concentration polarization and delaying the accumulation of impurities to form a filter cake layer. By utilizing the cross-flow filtration principle, the mass transfer effect during membrane filtration is greatly improved, effectively slowing down the membrane fouling process, extending the cleaning cycle and service life of the membrane module, reducing the operating and maintenance costs of the equipment, and ensuring the long-term stable and efficient operation of the entire membrane filtration device.

[0014] 2. The system employs multi-stage filtration, including a pre-filter, a plate-and-frame nanofiltration membrane, and a plate-and-frame reverse osmosis (RO) membrane, to effectively remove suspended solids, organic matter, salts, and other impurities from wastewater. This meets the diverse water quality requirements of different production stages. The three-way valve allows for flexible wastewater diversion, satisfying the water needs of processes with varying water quality requirements, avoiding excessive treatment that could lead to energy waste, and improving system operating efficiency. Attached Figure Description

[0015] Other features, objects, and advantages of this invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0016] Figure 1 This is a schematic diagram of the structure of a membrane filtration device for citric acid production according to the present invention;

[0017] Figure 2 This is a schematic diagram of the first and second filter boxes of a membrane filtration device for citric acid production according to the present invention.

[0018] Figure 3 This is a schematic diagram of the infusion cylinder structure of a membrane filtration device for citric acid production according to this utility model;

[0019] Figure 4 This is a schematic diagram of the conveying screw structure of a membrane filtration device for citric acid production according to the present invention;

[0020] Figure 5 This is a schematic diagram of the water pump structure of a membrane filtration device for citric acid production according to the present invention;

[0021] In the diagram: 1. Base plate; 2. First filter box; 201. Lower groove; 3. Water pump; 4. Second filter box; 5. Clean water outlet; 6. Infusion cylinder; 601. Filter port; 602. Connecting plate; 7. Sludge discharge port; 8. Liquid inlet; 9. Drive motor; 10. Primary filter screen; 11. Conveying screw; 12. Connecting plate; 13. Spring buffer column; 14. Silica gel scraper; 15. Plate and frame nanofiltration membrane; 16. First reflux pipe; 17. Plate and frame reverse osmosis (RO) membrane; 18. Second reflux pipe; 19. Booster pump; 20. Spray pipe; 2001. Spray head; 21. Liquid guide pipe; 22. Liquid outlet pipe; 23. Three-way valve; 24. Rubber sealing ring; 25. Mounting clamp. Detailed Implementation

[0022] To make the technical means, creative features, objectives and effects of this utility model easier to understand, the present utility model will be further described below in conjunction with specific embodiments.

[0023] Please see Figures 1 to 5This utility model provides a technical solution: a membrane filtration device for citric acid production, comprising a base plate 1, a first filter box 2 disposed on one side of the top of the base plate 1, and a plate-and-frame nanofiltration membrane 15 inserted at the center of the first filter box 2; a second filter box 4 disposed on the other side of the top of the base plate 1; a first return pipe 16 disposed at the center of both ends of the first filter box 2, with the outlet end of the first return pipe 16 connected to the top of the first filter box 2; and a second return pipe 18 disposed at the center of both ends of the second filter box 4, with the second return pipe 18... The discharge end is connected to the top of the second filter box 4. Both the first return pipe 16 and the second return pipe 18 are equipped with booster pumps 19. The top of the first filter box 2 is equipped with a liquid delivery cylinder 6, and a filter port 601 is opened at the bottom of the liquid delivery cylinder 6 near the first filter box 2. A primary filter screen 10 is installed in the filter port 601. The primary filter screen 10, plate and frame nanofiltration membrane 15 and plate and frame reverse osmosis RO membrane 17 are used for multi-stage filtration, which effectively removes suspended solids, organic matter, salt and other impurities in wastewater, and can meet the differentiated water quality requirements of different production links.

[0024] For example, a water pump 3 is installed at the center of the top of the base plate 1, and the input end of the water pump 3 is connected to the bottom of the first filter box 2. A spray pipe 20 is installed at the center of the top of the second filter box 4, and spray nozzles 2001 are evenly arranged at the bottom of the spray pipe 20. A three-way valve 23 is installed at the output end of the water pump 3, and the two liquid outlets of the three-way valve 23 are respectively connected to a liquid guide pipe 21 and a liquid outlet pipe 22. The liquid guide pipe 21 is connected to the spray pipe 20, and the liquid outlet pipe 22 can be directly connected to the water pipe of the production process with low water quality requirements, such as the raw material rinsing process. The three-way valve 23 realizes flexible diversion of wastewater to meet the water needs of processes with different water quality requirements, avoids excessive treatment and energy waste, and improves the system operating efficiency.

[0025] For example, a lower groove 201 is provided at the center of the top of the first filter box 2, and the shape of the lower groove 201 matches the external shape of the infusion cylinder 6. Rubber sealing rings 24 are provided on both sides of the semi-circular groove wall of the lower groove 201. Utilizing the good elasticity and flexibility of rubber, after the infusion cylinder 6 is installed, the rubber sealing rings 24 can tightly fill the gap between the lower groove 201 and the infusion cylinder 6 to form a reliable sealing structure and prevent liquid leakage.

[0026] Please see Figure 1 and Figure 2 The bottom of one end of the second filter box 4 is provided with a clean water outlet 5, and a plate and frame reverse osmosis membrane 17 is inserted into the center of the second filter box 4. The purified water produced by the clean water outlet 5 can be directly connected to the production process for cooling equipment, cleaning filter cloth and other processes. The purified water can be directly reused, reducing the amount of fresh water resources purchased by the enterprise and reducing water costs.

[0027] Please see Figure 2 and Figure 3 An inlet 8 is provided on the top of the infusion cylinder 6 near the first filter box 2, and a slag discharge port 7 is provided on the bottom of the infusion cylinder 6 away from the first filter box 2. A connecting plate 602 is provided at both ends of the infusion cylinder 6 near the lower groove 201, and the connecting plate 602 is connected to the top of the first filter box 2 by bolts. The connection plate 602 is connected to the first filter box 2 by bolts, making installation more convenient.

[0028] Please see Figure 4 The infusion cylinder 6 is equipped with a conveying screw 11, and a cleaning component is installed on the conveying screw 11. A drive motor 9 is provided on one side of the infusion cylinder 6, and the output end of the drive motor 9 is connected to the conveying screw 11. When the conveying screw 11 rotates, large particles of impurities intercepted by the primary filter screen 10 can be pushed towards the sludge discharge port 7 under the drive of the conveying screw 11, making it easy to clean.

[0029] Please see Figure 4 The cleaning assembly consists of a connecting plate 12, two spring buffer columns 13, a silicone scraper 14, and two mounting clamps 25. The two mounting clamps 25 are fixed to both ends of the delivery screw 11, and the spring buffer columns 13 extend vertically from the mounting clamps 25. The tops of the two spring buffer columns 13 are connected by the connecting plate 12, and the silicone scraper 14 is embedded on the outer side of the connecting plate 12. The silicone scraper 14 is in contact with the inner wall of the infusion cylinder 6. Under the action of the spring buffer columns 13, the silicone scraper 14 of the cleaning assembly is in close contact with the inner wall of the infusion cylinder 6 to remove residual impurities from the inner wall of the infusion cylinder 6.

[0030] Detailed Implementation: In use, citric acid production wastewater flows into the delivery cylinder 6 through the inlet 8. It is first pre-filtered by the primary filter screen 10 to intercept large particles of impurities. These impurities are pushed towards the discharge port 7 by the conveying screw 11. The silicone scraper 14 of the cleaning component, under the action of the spring buffer column 13, adheres tightly to the inner wall of the delivery cylinder 6 to remove residual impurities. The pre-filtered wastewater enters the first filter box 2, where it undergoes secondary filtration by the plate and frame nanofiltration membrane 15 to remove some salts and small organic molecules. At this point, the first return pipe 16 performs cross-flow filtration. Under the action of the booster pump 19, the incompletely filtered wastewater is not directly discharged but flows back parallel to the membrane surface at a certain flow rate for further filtration. This cross-flow filtration... This method creates turbulence on the membrane surface, reducing concentration polarization and preventing impurities from accumulating on the membrane surface to form a filter cake layer, thereby improving the membrane's filtration efficiency and service life. Wastewater flowing out of the first filter box 2 is pumped by the water pump 3 and passes through the three-way valve 23. Part of it is used for processes with low water quality requirements through the outlet pipe 22, while the other part enters the spray pipe 20 at the top of the second filter box 4 through the guide pipe 21 and is evenly sprayed by the nozzle 2001. Under the action of the plate and frame reverse osmosis membrane 17, it is deeply purified. Similarly, the second return pipe 18, in conjunction with the booster pump 19, allows the substandard wastewater to be returned for reprocessing in a cross-flow manner, continuously flushing the membrane surface to ensure the efficient operation of the reverse osmosis process. The purified water is discharged from the clean water outlet 5 for production.

[0031] Although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A membrane filtration device for citric acid production, comprising a base plate (1), characterized in that: A first filter box (2) is provided on one side of the top of the base plate (1), and a plate and frame nanofiltration membrane (15) is inserted into the center of the first filter box (2). A second filter box (4) is provided on the other side of the top of the base plate (1). A first return pipe (16) is provided at the center of both ends of the first filter box (2), and the discharge end of the first return pipe (16) is connected to the top of the first filter box (2). A second return pipe (18) is provided at the center of both ends of the second filter box (4), and the discharge end of the second return pipe (18) is connected to the top of the second filter box (4). A booster pump (19) is provided on both the first return pipe (16) and the second return pipe (18). An infusion cylinder (6) is installed on the top of the first filter box (2), and a filter port (601) is opened at the bottom of the infusion cylinder (6) near the first filter box (2). A primary filter screen (10) is provided in the filter port (601).

2. The membrane filtration device for citric acid production according to claim 1, characterized in that: A water pump (3) is installed at the center of the top of the base plate (1), and the input end of the water pump (3) is connected to the bottom of the first filter box (2). A spray pipe (20) is installed at the center of the top of the second filter box (4), and spray nozzles (2001) are evenly arranged at the bottom of the spray pipe (20). A three-way valve (23) is installed at the output end of the water pump (3), and the two liquid outlets of the three-way valve (23) are respectively connected to a liquid guide pipe (21) and a liquid outlet pipe (22). The liquid guide pipe (21) is connected to the spray pipe (20).

3. A membrane filtration device for citric acid production according to claim 1, characterized in that: The first filter box (2) has a lower groove (201) at the center of the top, and the shape of the lower groove (201) matches the external shape of the infusion cylinder (6). Both sides of the lower groove (201) are provided with rubber sealing rings (24).

4. A membrane filtration device for citric acid production according to claim 1, characterized in that: The bottom of one end of the second filter box (4) is provided with a clean water outlet (5), and a plate and frame reverse osmosis membrane (17) is inserted into the center of the second filter box (4).

5. A membrane filtration device for citric acid production according to claim 1, characterized in that: The infusion cylinder (6) has an inlet (8) on the side of the top of the cylinder close to the first filter box (2), and a slag discharge port (7) on the side of the bottom of the cylinder (6) away from the first filter box (2). Both ends of the infusion cylinder (6) are provided with connecting plates (602) near the lower groove (201), and the connecting plates (602) are connected to the top of the first filter box (2) by bolts.

6. A membrane filtration device for citric acid production according to claim 1, characterized in that: The infusion cylinder (6) is equipped with a conveying screw (11) inside, and a cleaning component is installed on the conveying screw (11). A drive motor (9) is provided on one side of the infusion cylinder (6), and the output end of the drive motor (9) is connected to the conveying screw (11).

7. A membrane filtration device for citric acid production according to claim 6, characterized in that: The cleaning assembly consists of a connecting plate (12), two spring buffer columns (13), a silicone scraper (14), and two mounting hoops (25). The two mounting hoops (25) are fixed to both ends of the delivery screw (11), and spring buffer columns (13) extend vertically from the mounting hoops (25). The tops of the two spring buffer columns (13) are connected by the connecting plate (12), and the silicone scraper (14) is fitted on the outside of the connecting plate (12). The silicone scraper (14) is in contact with the inner wall of the infusion cylinder (6).

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