Nanofiltration pipeline direct drinking water zero wastewater discharge integrated equipment and control method

Abstract

The invention discloses nanofiltration pipeline direct drinking water zero wastewater discharge integrated equipment and a control method, liquid level sensors are arranged on a water purification tank I and a water purification tank II, a backwashing pipeline is arranged between a tee joint and a nanofiltration membrane device, and a backwashing electric valve, a first pressure reducing valve and a filtering device are arranged on the backwashing pipeline; a produced water circulation pipeline is arranged between the first water purification tank and the nanofiltration membrane device, the inlet side of the produced water circulation pipeline is connected with a circulation water outlet of the nanofiltration membrane device, a produced water circulation electric valve is arranged on the produced water circulation pipeline, and an ozone activated carbon circulation pipeline is arranged between the three-way electric valve and the first water purification tank. The first water purification tank is connected with an ozone generation pipeline, and a nanofiltration water treatment outdoor circulation pipeline is arranged between the second water purification tank and one branch pipeline. The water flow taste and smell change caused by unified disinfection treatment of municipal tap water can be effectively eliminated, the use experience of a user is guaranteed, wastewater cannot be discharged to the outside of the system during the operation period of each process, and water resources are effectively saved.

Description

Technical Field

[0001] The present invention relates to the technical field of water treatment, and particularly relates to an integrated device for zero-wastewater discharge of nanofiltration pipeline direct drinking water and a control method therefor. Background Art

[0002] The drinking water in the municipal water supply system usually undergoes disinfection treatment to meet the water use standards. However, the disinfection treatment often brings changes in taste and odor to the water supply, which is not conducive to ensuring the water use experience of users. In order to solve the above problems uniformly, water treatment facilities need to be added at the water supply entrance of communities or building complexes. However, there is a lack of mature equipment of this type on the market at present, and the existing ordinary water treatment equipment has the problems of a large amount of wastewater generated during the water treatment process and serious waste of water resources. Therefore, there is an urgent need in the market for a device suitable for cluster applications and that does not cause water resource waste during the water treatment process. Summary of the Invention

[0003] The purpose of the present invention is to provide an integrated device for zero-wastewater discharge of nanofiltration pipeline direct drinking water and a control method therefor, which at least solves one of the technical problems existing in the prior art.

[0004] To solve the above technical problems, the present invention adopts the following technical solutions:

[0005] An integrated device for zero-wastewater discharge of nanofiltration pipeline direct drinking water according to the present invention includes a controller, a basic pipeline, and a raw water electric valve, a first water purification tank, a water purification pump, a three-way joint, a biological activated carbon tank, a three-way electric valve, a flowmeter, a nanofiltration membrane device, a water purification electric valve, a second water purification tank, and a water purification booster pump that are sequentially arranged on the basic pipeline from upstream to downstream. A plurality of branch pipelines are connected to the basic pipeline downstream of the water purification booster pump, and a water supply user port is connected to the branch pipelines. Liquid level sensors are respectively arranged on the first water purification tank and the second water purification tank. A backwashing pipeline is arranged between the three-way joint and the nanofiltration membrane device, and a backwashing electric valve, a first pressure reducing valve, and a filtering device are arranged on the backwashing pipeline. A product water circulation pipeline is arranged between the first water purification tank and the nanofiltration membrane device. The inlet side of the product water circulation pipeline is connected to the circulating water outlet of the nanofiltration membrane device, and a product water circulation electric valve is arranged on the product water circulation pipeline. An ozone-activated carbon circulation pipeline is arranged between the three-way electric valve and the first water purification tank. An ozone generation pipeline is connected to the first water purification tank, and an ozone circulation pump, an ozone electric valve, a second pressure reducing valve, an ozone injector, and a micro-nano bubble generator are arranged on the ozone generation pipeline. The micro-nano bubble generator has an ozone inlet hole, and the ozone inlet hole is connected to the outlet of the ozone injector. A nanofiltration water treatment outdoor circulation pipeline is arranged between the second water purification tank and one of the branch pipelines. A first scale inhibitor device, a pipeline large circulation electric valve, a first magnetized water generator, a first precision filter, a third pressure reducing valve, a remote pressure gauge, and a stop valve are sequentially arranged on the nanofiltration water treatment outdoor circulation pipeline. The controller is electrically connected to the raw water electric valve, the water purification pump, the three-way electric valve, the flowmeter, the water purification electric valve, the liquid level sensor, the backwashing electric valve, the product water circulation electric valve, the ozone circulation pump, the ozone electric valve, the pipeline large circulation electric valve, and the remote pressure gauge.

[0006] Further, the nanofiltration membrane device includes a housing and a hollow nanofiltration membrane tube coaxially installed in the housing. The housing is provided with a front-end water inlet, a circulating water outlet, and a rear-end purified water outlet. The front-end water inlet and the circulating water outlet are communicated with the inner cavity of the hollow nanofiltration membrane tube, and the rear-end purified water outlet is communicated with the outside of the hollow nanofiltration membrane tube. The basic pipeline is connected to the front-end water inlet and the rear-end purified water outlet.

[0007] Further, a communicating pipeline is connected in parallel to the basic pipeline. One end of the communicating pipeline is connected to the basic pipeline near the upstream side of the water purification electric valve, and the other end is connected to the basic pipeline near the outlet side of the water purification booster pump. A manual valve is arranged on the communicating pipeline, and the communicating pipeline is used for backwashing the second water purification tank.

[0008] Further, a raw water stop valve and a second precision filter are provided on the basic pipeline upstream of the raw water electric valve. A second magnetization water activator and a first ultraviolet disinfection device are provided between the raw water electric valve and the first water purification tank. A first pressure sensor and a pressure gauge are provided between the tee joint and the biological activated carbon tank. A pressure gauge, a first sampling valve and a third precision filter are provided between the biological activated carbon tank and the flowmeter. A check valve and a second scale inhibitor device are provided between the flowmeter and the nanofiltration membrane device. A second sampling valve and a pressure gauge are provided between the nanofiltration membrane device and the purified water electric valve. A post - activated carbon tank and a filter are provided between the purified water electric valve and the second water purification tank. A second ultraviolet disinfection device is provided between the second water purification tank and the purified water pressurizing pump. A pressurizing pump check valve and a second pressure sensor are provided between the purified water pressurizing pump and the branch pipeline. The first pressure sensor and the second pressure sensor are respectively electrically connected to the controller.

[0009] Further, a third sampling valve and a water quality monitor are provided on both the first water purification tank and the second water purification tank, and the water quality monitor is electrically connected to the controller.

[0010] Further, a breather valve is provided on the second water purification tank.

[0011] Further, the filtering device is a ceramic membrane filter.

[0012] Further, a ceramic membrane filter is provided on the ozone - activated carbon circulation pipeline. The inlet of the ozone injector is connected to an ozone supply line, and an ozone control box responsible for the on - off of ozone supply is provided at the upstream end of the ozone supply line.

[0013] The present invention also provides a control method for a nanofiltration pipeline direct drinking water zero - wastewater discharge integrated device. Using the nanofiltration pipeline direct drinking water zero - wastewater discharge integrated device described above, the control method includes:

[0014] The controller controls the raw water electric valve to open. Municipal water supply enters the first water purification tank after passing through the second precision filter, the second magnetization water activator and the first ultraviolet disinfection device. When the liquid level in the first water purification tank rises to the middle level, the purified water pump starts to work. The water flow in the first water purification tank is pumped out and reaches the front - end water inlet of the nanofiltration membrane device after passing through the biological activated carbon tank, the third precision filter, the flowmeter and the second scale inhibitor device. The water flow enters the inner cavity of the hollow nanofiltration membrane tube from the front - end water inlet, and then passes through the hollow nanofiltration membrane tube in all directions to complete filtration and enter the rear - end purified water outlet. The water flow sent out from the rear - end purified water outlet enters the second water purification tank after passing through the post - activated carbon tank and the filter. The water flow in the second water purification tank can be sent to each branch pipeline by the purified water pressurizing pump for use by the user terminal;

[0015] When the electric valve for water purification is opened or closed, the water purification pump can extract the water flow in the first water purification tank and return it to the first water purification tank through the water production circulation pipeline. In this process, the water flow will be purified by the biological activated carbon tank, the third precision filter and the nanofiltration membrane device to form a water production circulation system for the first water purification tank. The water that has been continuously treated is cleaner and has lower pollutant content.

[0016] During the water production operation, the flow meter feeds back the flow information to the controller. When the accumulated water production reaches the set total flow and the liquid level of the second water purification tank is in a high liquid level state, the water purification electric valve is controlled to close, the water production circulation electric valve is controlled to fully open, the water purification pump is running, and the three-way electric valve is switched to the ozone activated carbon circulation pipeline connection state. The ozone generation pipeline is running, and the ozone production process is as follows: the ozone circulation pump extracts part of the water in the first water purification tank and then reaches the micro-nano bubble generator. The ozone gas and micro-nano bubbles sent by the ozone injector are simultaneously sprayed into the first water purification tank to form ozone micro-nano bubble water. The water purification pump extracts the ozone micro-nano bubble water in the first water purification tank and sends it to the biological activated carbon tank. The water flow sent by the biological activated carbon tank returns to the first water purification tank from the ozone activated carbon circulation pipeline to form an ozone activated carbon circulation system. The ozone activated carbon circulation system is set to run at night;

[0017] The backwash cycle can also be operated during the operation of the ozone production process. The backwash cycle process is: the backwash electric valve is controlled to open, and the ozone micro-nano bubble water flows into the backwash pipeline and passes through the ceramic membrane filter. Then it enters the rear water purification port and reversely passes through the hollow nanofiltration membrane tube to complete the backwash sterilization and disinfection of the hollow nanofiltration membrane tube. The backwash water flows out through the circulating water outlet of the nanofiltration membrane device and finally flows into the water production circulation pipeline through the water production circulation electric valve, and then re-enters the water purification tank to form a backwash circulation system.

[0018] Furthermore, information on the rise or fall of the liquid levels in the first and second clean water tanks is fed back to the controller for regulating the operation of the system. When the first clean water tank drops from a high liquid level to a medium liquid level, the raw water electric valve opens and the first clean water tank is replenished with water; when the liquid level in the first clean water tank drops to a low liquid level, the clean water pump stops working and the first clean water tank no longer discharges water; when the second clean water tank drops from a high liquid level to a medium liquid level, the clean water electric valve opens, and the clean water pump starts working to replenish water to the second clean water tank; when the liquid level in the second clean water tank rises to a high liquid level, the clean water electric valve closes, and the clean water pump stops working; when the liquid level in the second clean water tank drops below the medium liquid level, the clean water booster pump stops working, and when the second clean water tank rises to the medium liquid level again, the controller allows the clean water booster pump to start supplying water, and when the liquid level in the second clean water tank rises to a high liquid level, the water purification and production work is completed.

[0019] Compared with the prior art, the beneficial technical effects of the present invention are:

[0020] The integrated device for zero wastewater discharge of nanofiltration pipeline direct drinking water and its control method of the present invention can effectively remove harmful substances in municipal water supply by setting multi-stage filtration treatment measures including biological activated carbon tank and nanofiltration membrane device, eliminate the change of water flow taste and smell caused by unified disinfection treatment of municipal tap water, and ensure the user experience. At the same time, no wastewater is discharged outside the system during the operation of each process, effectively saving water resources. Among them, the ozone-activated carbon circulation pipeline can also realize the activation and regeneration of biological activated carbon under control. The overall operation of the system is stable and the maintenance cost is low, which is suitable for popularization and use. Brief Description of the Drawings

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0022] Figure 1 It is a schematic structural diagram of the integrated device for zero wastewater discharge of nanofiltration pipeline direct drinking water in Embodiment 1 of the present invention;

[0023] Figure 2 It is a schematic working principle diagram of the hollow nanofiltration membrane tube in the integrated device for zero wastewater discharge of nanofiltration pipeline direct drinking water in Embodiment 1 of the present invention.

[0024] Description of the reference numerals in the drawings: 1. Basic pipeline; 2. Raw water electric valve; 3. First clean water tank; 4. Clean water pump; 5. Three-way joint; 6. Biological activated carbon tank; 7. Three-way electric valve; 8. Flowmeter; 9. Nanofiltration membrane device; 10. Clean water electric valve; 11. Second clean water tank; 12. Clean water booster pump; 13. Branch pipeline; 14. Liquid level sensor; 15. Backwashing pipeline; 16. Backwashing electric valve; 17. First pressure reducing valve; 18. Ceramic membrane filter; 19. Housing; 20. Hollow nanofiltration membrane tube; 21. Product water circulation pipeline; 22. Product water circulation electric valve; 23. Ozone-activated carbon circulation pipeline; 24. Ozone generation pipeline; 25. Ozone circulation pump; 26. Ozone electric valve; 27. Second pressure reducing valve; 28. Ozone injector; 29. Micro-nano bubble generator; 30. Ozone supply line; 31. Outdoor circulation pipeline for nanofiltration water treatment; 32. First scale inhibitor device; 33. Main pipeline large circulation electric valve; 34. First magnetized water generator; 35. First precision filter; 36. Third pressure reducing valve; 37. Remote pressure gauge; 38. Globe valve; 39. Connecting pipeline; 40. Manual valve; 41. Raw water stop valve; 42. Second precision filter; 43. Second magnetized water generator; 44. First ultraviolet disinfection device; 45. First pressure sensor; 46. First sampling valve; 47. Third precision filter; 48. Check valve; 49. Second scale inhibitor device; 50. Second sampling valve; 51. Post-activation carbon tank; 52. Filter; 53. Second ultraviolet disinfection device; 54. Booster pump check valve; 55. Second pressure sensor; 56. Third sampling valve; 57. Water quality monitor; 58. Breather valve. Detailed implementation mode

[0025] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the drawings, wherein the same or similar reference numerals indicate the same or similar elements or elements with the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present invention and should not be construed as a limitation of the present invention.

[0026] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by terms such as "length", "width", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "a plurality" means two or more unless otherwise specifically defined.

[0027] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal communication of two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0028] The following will, with reference to the accompanying drawings, detail the technical solutions provided by each embodiment of the present invention.

[0029] Embodiment 1

[0030] As Figure 1 、 Figure 2 shown, the integrated device for zero wastewater discharge of nanofiltration pipeline direct drinking water in this Embodiment 1 includes a controller, a basic pipeline 1, a raw water electric valve 2, a first water purification tank 3, a water purification pump 4, a tee 5, a biological activated carbon tank 6, a tee electric valve 7, a flowmeter 8, a nanofiltration membrane device 9, a water purification electric valve 10, a second water purification tank 11, and a water purification booster pump 12, which are sequentially arranged on the basic pipeline 1 from upstream to downstream. A plurality of branch pipelines 13 are connected to the basic pipeline 1 downstream of the water purification booster pump 12, and the water supply user port is connected to the branch pipeline 13. Liquid level sensors 14 are respectively arranged on the first water purification tank 3 and the second water purification tank 11.

[0031] Preferably, the liquid level sensor 14 is a pressure type liquid level sensor, and both the water purification pump 4 and the water purification booster pump 12 are variable frequency pumps. Among them, there are two water purification booster pumps 12, which can be enabled simultaneously or one is in standby and the other is in use; the flowmeter 8 is a remote metal float flowmeter.

[0032] Among them, an anti - washing pipeline 15 is arranged between the tee 5 and the nanofiltration membrane device 9. An anti - washing electric valve 16, a first pressure reducing valve 17, and a filtering device are arranged on the anti - washing pipeline 15. Specifically, the filtering device is a ceramic membrane filter 18.

[0033] Moreover, the nanofiltration membrane device 9 includes a housing 19 and a hollow nanofiltration membrane tube 20 coaxially installed in the housing 19. The housing 19 is provided with a front - end water inlet, a circulating water outlet, and a rear - end purified water outlet. The front - end water inlet and the circulating water outlet are communicated with the inner side of the hollow nanofiltration membrane tube 20, and the rear - end purified water outlet is communicated with the outer side of the hollow nanofiltration membrane tube 20. The basic pipeline 1 is connected to the front - end water inlet and the rear - end purified water outlet.

[0034] In this embodiment, a product water circulation pipeline 21 is further arranged between the first water purification tank 3 and the nanofiltration membrane device 9. The inlet side of the product water circulation pipeline 21 is connected to the circulating water outlet, and a product water circulation electric valve 22 is arranged on the product water circulation pipeline 21.

[0035] At this time, an ozone-activated carbon circulation pipeline 23 is provided between the three-way electric valve 7 and the first clean water tank 3. A ceramic membrane filter 18 is also provided on the ozone-activated carbon circulation pipeline 23. An ozone generation pipeline 24 is further connected to the first clean water tank 3. An ozone circulation pump 25, an ozone electric valve 26, a second pressure reducing valve 27, an ozone injector 28, and a micro-nano bubble generator 29 are provided on the ozone generation pipeline 24. The micro-nano bubble generator 29 has an ozone inlet hole, and the ozone inlet hole is connected to the outlet of the ozone injector 28. The inlet of the ozone injector 28 is connected to an ozone supply line 30. An ozone control box is provided at the upstream end of the ozone supply line 30 to be responsible for the on-off of ozone supply.

[0036] Specifically, the controller is electrically connected to the raw water electric valve 2, the clean water pump 4, the three-way electric valve 7, the flow meter 8, the clean water electric valve 10, the liquid level sensor 14, the backwash electric valve 16, the product water circulation electric valve 22, the ozone circulation pump 25, and the ozone electric valve 26. Preferably, the controller is a PLC controller.

[0037] In this embodiment, a nanofiltration water treatment outdoor circulation pipeline 31 is further provided between the second clean water tank 11 and a certain pipeline 13 to realize the timed circulation process of the outdoor pipeline network at the user end. Specifically, a first scale inhibitor device 32, a pipeline network large circulation electric valve 33, a first magnetized water generator 34, a first precision filter 35, a third pressure reducing valve 36, a remote pressure gauge 37, and a stop valve 38 are provided on the nanofiltration water treatment outdoor circulation pipeline 31. The pipeline network large circulation electric valve 33 and the remote pressure gauge 37 are also electrically connected to the controller. Preferably, the first scale inhibitor device 32 is a filter screen.

[0038] The water output from the second clean water tank 11 is sent to the pipeline 13, and the return water flows reversely from a selected pipeline 13 into the second clean water tank 11, realizing the timed large circulation of the supply and return water of the outdoor pipeline network at the user end. For example, it can be set that the nanofiltration water treatment outdoor circulation pipeline circulates no more than once every 12 hours, circulates a total of 2 times a day, and each circulation lasts for 2 - 4 hours to avoid the formation of stagnant water.

[0039] Moreover, a connecting pipeline 39 is connected in parallel to the basic pipeline 1. One end of the connecting pipeline 39 is connected to the basic pipeline 1 near the upstream side of the clean water electric valve 10, and the other end is connected to the basic pipeline 1 near the outlet side of the clean water pressurizing pump 12. A manual valve 40 is provided on the connecting pipeline 39. The connection of the connecting pipeline 39 in cooperation with the closing of the clean water electric valve 10 can be used for the backwash of the second clean water tank 11.

[0040] On the basic pipeline 1 upstream of the raw water electric valve 2, a raw water stop valve 41 and a second precision filter 42 are further provided. On the basic pipeline 1 between the raw water electric valve 2 and the first purified water tank 3, a second magnetized water generator 43 and a first ultraviolet disinfection device 44 are further provided. On the basic pipeline 1 between the three-way joint 5 and the biological activated carbon tank 6, a first pressure sensor 45 and a pressure gauge are further provided. The first pressure sensor 45 is electrically connected to the controller; on the basic pipeline 1 between the biological activated carbon tank 6 and the flowmeter 8, a pressure gauge, a first sampling valve 46 and a third precision filter 47 are further provided; on the basic pipeline 1 between the flowmeter 8 and the nanofiltration membrane device 9, a check valve 48 and a second scale inhibitor device 49 are further provided. The second scale inhibitor device 49 is also a filter screen; on the basic pipeline 1 between the nanofiltration membrane device 9 and the purified water electric valve 10, a second sampling valve 50 and a pressure gauge are provided; on the basic pipeline 1 between the purified water electric valve 10 and the second purified water tank 11, a post-activated carbon tank 51 and a filter 52 are further provided. The filter 52 is a folded precision filter; on the basic pipeline 1 between the second purified water tank 11 and the purified water booster pump 12, a second ultraviolet disinfection device 53 is provided; on the basic pipeline 1 between the purified water booster pump 12 and the branch pipeline 13, a booster pump check valve 54 and a second pressure sensor 55 electrically connected to the controller are provided.

[0041] Moreover, a third sampling valve 56 and a water quality monitor 57 are provided on both the first purified water tank 3 and the second purified water tank 11. The water quality monitor 57 is electrically connected to the controller. A breather valve 58 is separately provided on the second purified water tank 11.

[0042] The working process of the nanofiltration pipeline direct drinking water zero-waste discharge integrated equipment of this Embodiment 1 is as follows: The controller controls the raw water electric valve 2 to open. The municipal water supply enters the first purified water tank 3 after passing through the second precision filter 42, the second magnetized water generator 43 and the first ultraviolet disinfection device 44. When the liquid level in the first purified water tank 3 rises to the middle liquid level, the purified water pump 4 starts to work. The water flow in the first purified water tank 3 is pumped out and reaches the front-end water inlet of the nanofiltration membrane device 9 after passing through the biological activated carbon tank 6, the precision filter 47, the flowmeter 8 and the second scale inhibitor device 49. The water flow enters the inner cavity of the hollow nanofiltration membrane tube 20 from the front-end water inlet, then passes through the hollow nanofiltration membrane tube 20 in all directions to complete filtration and enters the rear-end purified water outlet. The water flow sent out from the rear-end purified water outlet enters the second purified water tank 11 after passing through the post-activated carbon tank 51 and the filter 52. The water flow in the second purified water tank 11 can be sent to each branch pipeline 13 by the purified water booster pump 12 for use by the user terminal.

[0043] When the purified water electric valve 10 is opened or closed, the purified water pump 4 can pump out the water flow in the first purified water tank 3 and return it to the first purified water tank 3 through the product water circulation pipeline 21. During this process, the water flow will pass through the purification treatment of the biological activated carbon tank 6, the third precision filter 47 and the nanofiltration membrane device 9 to form a product water circulation system for the first purified water tank 3. The continuously treated water will be cleaner and have a lower pollutant content.

[0044] The information on the rise or fall of the liquid levels in the first water purification tank 3 and the second water purification tank 11 is fed back to the controller for regulating the operation of the system. Specifically, when the liquid level in the first water purification tank 3 drops from the high level to the middle level, the raw water electric valve 2 opens to replenish water to the first water purification tank 3; when the liquid level in the first water purification tank 3 drops to the low level, the water purification pump 4 stops working and the first water purification tank 3 stops discharging water; when the liquid level in the second water purification tank 11 drops from the high level to the middle level, the water purification electric valve 10 opens and the water purification pump 4 starts working to replenish water to the second water purification tank 11; when the liquid level in the second water purification tank 11 rises to the high level, the water purification electric valve 10 closes and the water purification pump 4 stops working; when the liquid level in the second water purification tank 11 drops from the middle level to the low level, the water purification booster pump 12 stops working, and when the liquid level in the second water purification tank 11 rises back to the middle level again, the controller allows the water purification booster pump 12 to start supplying water, and when the liquid level in the second water purification tank 11 rises to the high level, the current water purification production work is completed.

[0045] It should be noted that when the equipment produces water, the water production circulation electric valve 22 provided on the water production circulation pipeline 21 remains at a certain opening degree, such as 20%. The purified water generated by the filtration of water by the nanofiltration membrane device 9 enters the second water purification tank 11. The water flow that fails to pass through the hollow nanofiltration membrane tube 20 is sent out from the circulating water outlet, enters the water production circulation pipeline 21, and returns to the first water purification tank 3 for subsequent treatment. This cooperation avoids waste water discharge and effectively saves water resources.

[0046] During the water production operation, the flowmeter 8 feeds back the flow information to the controller. When the cumulative water production reaches the set total flow and the liquid level in the second water purification tank 11 is in the high level state, the water purification electric valve 10 is controlled to close, the water production circulation electric valve 21 is controlled to open fully, the water purification pump 4 operates, and the three-way electric valve 7 switches to the connected state of the ozone-activated carbon circulation pipeline 23, and the ozone generation pipeline 24 operates. The ozone generation process is as follows: The ozone circulation pump 25 pumps out part of the water in the first water purification tank 3 and then reaches the micro-nano bubble generator 29. The ozone gas sent out by the ozone injector 28 and the micro-nano bubbles are simultaneously sprayed into the first water purification tank 3 to form ozone micro-nano bubble water. The water purification pump 4 pumps out the ozone micro-nano bubble water in the first water purification tank 3 and sends it to the biological activated carbon tank 6. The ozone micro-nano bubbles generated by the cooperation of the micro-nano bubble generator 29 and the ozone generator 28 can not only purify harmful substances but also oxidize and activate the biological activated carbon to restore its activity. The water flow sent out by the biological activated carbon tank 6 returns to the first water purification tank 3 from the ozone-activated carbon circulation pipeline 23 to form an ozone-activated carbon circulation system, and the ozone-activated carbon circulation system is set to operate at night.

[0047] During the operation of the above process, the backwash cycle can also be operated, specifically: the backwash electric valve 16 is controlled to open, the ozone micro-nano bubble water flows into the backwash pipeline 15, passes through the ceramic membrane filter 18, enters the rear end water purification port and reversely passes through the hollow nanofiltration membrane tube 20, completing the backwash sterilization and disinfection of the hollow nanofiltration membrane tube 20, the backwash water flows out through the circulating water outlet of the nanofiltration membrane device 9 and finally flows into the water production circulation pipeline 21 through the water production circulation electric valve 22 and then re-enters the water purification tank 3, forming a backwash circulation system.

[0048] During actual use, the nanofiltration membrane device 9 can be backwashed and disinfected regularly according to the total flow rate of water production. Regular membrane backwashing will extend the life of the hollow nanofiltration membrane tube 20 and restore the water production rate of the hollow nanofiltration membrane tube 20.

[0049] When the nanofiltration pipeline direct drinking water zero wastewater discharge integrated equipment of this embodiment 1 encounters conflicts during operation, the priority order is: water replenishment of the second water purification tank 11, ozone activated carbon circulation system, backwashing system and nanofiltration water treatment outdoor circulation system.

[0050] Example 2

[0051] The control method of the integrated device for direct drinking water from nanofiltration pipeline with zero wastewater discharge in this embodiment 2 adopts the integrated device for direct drinking water from nanofiltration pipeline with zero wastewater discharge, and the control method includes:

[0052] The controller controls the raw water electric valve 2 to open, and the municipal water supply enters the first water purification tank 3 after passing through the second precision filter 42, the second magnetized water activator 43 and the first ultraviolet disinfector 44. When the liquid level in the first water purification tank 3 rises to the middle liquid level, the water purification pump 4 starts to work, and the water flow in the first water purification tank 3 is pumped out and passes through the biological activated carbon tank 6, the third precision filter 47, the flow meter 8 and the second scale prevention device 49 to reach the front water inlet of the nanofiltration membrane device 9. The water flows into the inner cavity of the hollow nanofiltration membrane tube 20 from the front water inlet, and then passes through the hollow nanofiltration membrane tube 20 to complete the filtration and enter the rear water purification port. The water sent out from the rear water purification port passes through the post-activated carbon tank 51 and the filter 52 and enters the second water purification tank 11. The water flow in the second water purification tank 11 can be sent to each branch pipeline 13 by the water purification booster pump 12 for use by the user end;

[0053] When the water purification electric valve 10 is opened or closed, the water purification pump 4 can extract the water flow in the water purification tank 3 and return it to the water purification tank 3 through the water production circulation pipeline 21. In this process, the water flow will be purified by the biological activated carbon tank 6, the third precision filter 47 and the nanofiltration membrane device 9 to form a water production circulation system for the water purification tank 3. The water that has been continuously treated is cleaner and has a lower content of pollutants.

[0054] During the water production operation, the flow meter 8 feeds back the flow information to the controller. When the accumulated water production reaches the set total flow and the liquid level of the second water purification tank 11 is in a high liquid level state, the water purification electric valve 10 is controlled to be closed, the water production circulation electric valve 21 is controlled to be fully opened, the water purification pump 4 is running, the three-way electric valve 7 is switched to the ozone activated carbon circulation pipeline 23 connection state, and the ozone generation pipeline 24 is running. The ozone production process is as follows: the ozone circulation pump 25 extracts part of the water in the first water purification tank 3 and then reaches the micro-nano bubble generator 29, the ozone gas and micro-nano bubbles sent by the ozone injector 28 are simultaneously sprayed into the first water purification tank 3 to form ozone micro-nano bubble water, the water purification pump 4 extracts the ozone micro-nano bubble water in the first water purification tank 3 and sends it to the biological activated carbon tank 6, the water flow sent by the biological activated carbon tank 6 returns from the ozone activated carbon circulation pipeline 23 to the first water purification tank 3, forming an ozone activated carbon circulation system, and the ozone activated carbon circulation system is set to operate at night;

[0055] The backwash cycle can also be operated during the operation of the ozone production process. The backwash cycle process is: the backwash electric valve 16 is controlled to open, and the ozone micro-nano bubble water flows into the backwash pipeline 15 and then passes through the ceramic membrane filter 18 to enter the rear end water purification port and reversely pass through the hollow nanofiltration membrane tube 20, completing the backwash sterilization and disinfection of the hollow nanofiltration membrane tube 20. The backwash water flows out through the circulating water outlet of the nanofiltration membrane device 9 and finally flows into the water production circulation pipeline 21 through the water production circulation electric valve 22, and then re-enters the water purification tank 3, forming a backwash circulation system.

[0056] Preferably, the information of the liquid level rise or fall in the first clean water tank 3 and the second clean water tank 11 is fed back to the controller for regulating the operation of the system. When the first clean water tank 3 drops from a high liquid level to a medium liquid level, the raw water electric valve 2 opens and the first clean water tank 3 is replenished with water; when the liquid level in the first clean water tank 3 drops to a low liquid level, the clean water pump 4 stops working and the first clean water tank 3 no longer discharges water; when the second clean water tank 11 drops from a high liquid level to a medium liquid level, the clean water electric valve 10 opens, and the clean water pump 4 starts working to replenish water to the second clean water tank 11; when the liquid level in the second clean water tank 11 rises to a high liquid level, the clean water electric valve 10 closes, and the clean water pump 4 stops working; when the liquid level in the second clean water tank 11 drops below the medium liquid level, the clean water booster pump 12 stops working, and when the second clean water tank 11 rises to the medium liquid level again, the controller allows the clean water booster pump 12 to start supplying water, and when the liquid level in the second clean water tank 11 rises to a high liquid level, the water purification and water production work is completed.

[0057] The integrated device and control method for zero wastewater discharge of nanofiltration pipeline direct drinking water of the present invention can effectively remove harmful substances in municipal water supply by setting up multi-stage filtration treatment measures including biological activated carbon tank and nanofiltration membrane device, eliminate the change of water flow taste and smell caused by unified disinfection treatment of municipal tap water, ensure the user experience. At the same time, no wastewater is discharged outside the system during the operation of each process, effectively saving water resources. Among them, the ozone-activated carbon circulation pipeline can also realize the activation and regeneration of biological activated carbon under control. The overall system operates stably and has low maintenance cost, which is suitable for popularization and use.

[0058] The embodiments described above are only used to describe the preferred mode of the present invention, and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the claims of the present invention.

Claims

1. A nanofiltration pipeline direct drinking water zero wastewater discharge integrated equipment, characterized in that: It includes a controller, a basic pipeline, and a raw water electric valve, a clean water tank, a clean water pump, a tee, a biological activated carbon tank, a three-way electric valve, a flow meter, a nanofiltration membrane device, a clean water electric valve, a clean water tank and a clean water booster pump which are arranged on the basic pipeline in sequence from upstream to downstream. A plurality of branch pipelines are connected to the basic pipeline downstream of the clean water booster pump, and a water supply user port is connected to the branch pipeline. Liquid level sensors are respectively arranged on the clean water tank and the clean water tank. A backwash pipeline is arranged between the tee and the nanofiltration membrane device. A backwash electric valve, a first pressure reducing valve and a filtering device are arranged on the backwash pipeline. A water production circulation pipeline is arranged between the clean water tank and the nanofiltration membrane device. The inlet side of the water production circulation pipeline is connected to the circulating water outlet of the nanofiltration membrane device. A water production circulation electric valve is arranged on the water production circulation pipeline. An ozone activated carbon circulation pipeline is arranged between the three-way electric valve and the clean water tank. An ozone generating pipeline is connected to the first water purification tank, and an ozone circulating pump, an ozone electric valve, a second pressure reducing valve, an ozone injector and a micro-nano bubble generator are arranged on the ozone generating pipeline. The micro-nano bubble generator has an ozone air inlet, and the ozone air inlet is connected to the outlet of the ozone injector. A nanofiltration water treatment outdoor circulating pipeline is arranged between the second water purification tank and one of the branch pipelines. The first scale prevention device, the large circulation electric valve of the pipeline network, the first magnetized water activator, the first precision filter, the third pressure reducing valve, a remote pressure gauge and a stop valve are arranged in sequence on the outdoor circulating pipeline of the nanofiltration water treatment. The controller is electrically connected to the raw water electric valve, the water purification pump, the three-way electric valve, the flow meter, the water purification electric valve, the liquid level sensor, the backwash electric valve, the water production circulation electric valve, the ozone circulating pump, the ozone electric valve, the large circulation electric valve of the pipeline network and the remote pressure gauge respectively.

2. The nanofiltration pipeline direct drinking water zero wastewater discharge integrated equipment according to claim 1 is characterized in that: The nanofiltration membrane device includes a shell and a hollow nanofiltration membrane tube coaxially installed in the shell. The shell is provided with a front water inlet, a circulating water outlet and a rear water purification outlet. The front water inlet and the circulating water outlet are connected to the inner cavity of the hollow nanofiltration membrane tube, and the rear water purification outlet is connected to the outside of the hollow nanofiltration membrane tube. The basic pipeline is connected to the front water inlet and the rear water purification outlet.

3. The nanofiltration pipeline direct drinking water zero wastewater discharge integrated equipment according to claim 1 is characterized in that: A connecting pipeline is connected in parallel to the basic pipeline, one end of which is connected to the basic pipeline close to the upstream side of the water purification electric valve, and the other end is connected to the basic pipeline close to the outlet side of the water purification booster pump. A manual valve is provided on the connecting pipeline, and the connecting pipeline is used for backwashing of the second water purification tank.

4. The nanofiltration pipeline direct drinking water zero wastewater discharge integrated equipment according to claim 1 is characterized in that: A raw water shut-off valve and a second precision filter are arranged on the basic pipeline upstream of the raw water electric valve, a second magnetized water activator and a first ultraviolet sterilizer are arranged between the raw water electric valve and the first water purification tank, a first pressure sensor and a pressure gauge are arranged between the tee and the biological activated carbon tank, a pressure gauge, a first sampling valve and a third precision filter are arranged between the biological activated carbon tank and the flow meter, a check valve and a second scale prevention device are arranged between the flow meter and the nanofiltration membrane device, a second sampling valve and a pressure gauge are arranged between the nanofiltration membrane device and the water purification electric valve, a post-activated carbon tank and a filter are arranged between the water purification electric valve and the second water purification tank, a second ultraviolet sterilizer is arranged between the second water purification tank and the water purification booster pump, a booster pump check valve and a second pressure sensor are arranged between the water purification booster pump and the branch pipeline, and the first pressure sensor and the second pressure sensor are electrically connected to the controller respectively.

5. The nanofiltration pipeline direct drinking water zero wastewater discharge integrated equipment according to claim 1 is characterized in that: The first purified water tank and the second purified water tank are both provided with a third sampling valve and a water quality monitor, and the water quality monitor is electrically connected to the controller.

6. The nanofiltration pipeline direct drinking water zero wastewater discharge integrated equipment according to claim 1 is characterized in that: The second water purification tank is provided with a breathing valve.

7. The nanofiltration pipeline direct drinking water zero wastewater discharge integrated equipment according to claim 1 is characterized in that: The filtering device is a ceramic membrane filter.

8. The nanofiltration pipeline direct drinking water zero wastewater discharge integrated equipment according to any one of claims 1 to 7, characterized in that: A ceramic membrane filter is arranged on the ozone activated carbon circulation pipeline, an ozone supply line is connected to the inlet of the ozone injector, and an ozone control box responsible for switching on and off the ozone supply is arranged at the upstream end of the ozone supply line.

9. A control method for a nanofiltration pipeline direct drinking water zero wastewater discharge integrated device, characterized in that: The nanofiltration pipeline direct drinking water zero wastewater discharge integrated device according to any one of claims 1 to 8 is used, and the control method comprises: The controller controls the raw water electric valve to open, and the municipal water enters the first water purification tank after passing through the second precision filter, the second magnetized water activator and the first ultraviolet disinfector. When the liquid level in the first water purification tank rises to the middle liquid level, the water purification pump starts to work, and the water flow in the first water purification tank is pumped out and passes through the biological activated carbon tank, the third precision filter, the flow meter and the second scale prevention device to reach the front water inlet of the nanofiltration membrane device. The water flows into the inner cavity of the hollow nanofiltration membrane tube from the front water inlet, and then passes through the hollow nanofiltration membrane tube to complete the filtration and enter the rear water purification port. The water sent out from the rear water purification port passes through the post-activated carbon tank and the filter and enters the second water purification tank. The water flow in the second water purification tank can be pumped to each branch pipeline by the water purification booster pump for use by the user end; When the electric valve for water purification is opened or closed, the water purification pump can extract the water flow in the first water purification tank and return it to the first water purification tank through the water production circulation pipeline. In this process, the water flow will be purified by the biological activated carbon tank, the third precision filter and the nanofiltration membrane device to form a water production circulation system for the first water purification tank. The water that has been continuously treated is cleaner and has lower pollutant content. During the water production operation, the flow meter feeds back the flow information to the controller. When the accumulated water production reaches the set total flow and the liquid level of the second water purification tank is in a high liquid level state, the water purification electric valve is controlled to close, the water production circulation electric valve is controlled to fully open, the water purification pump is running, and the three-way electric valve is switched to the ozone activated carbon circulation pipeline connection state. The ozone generation pipeline is running, and the ozone production process is as follows: the ozone circulation pump extracts part of the water in the first water purification tank and then reaches the micro-nano bubble generator. The ozone gas and micro-nano bubbles sent by the ozone injector are simultaneously sprayed into the first water purification tank to form ozone micro-nano bubble water. The water purification pump extracts the ozone micro-nano bubble water in the first water purification tank and sends it to the biological activated carbon tank. The water flow sent by the biological activated carbon tank returns to the first water purification tank from the ozone activated carbon circulation pipeline to form an ozone activated carbon circulation system. The ozone activated carbon circulation system is set to run at night; The backwash cycle can also be operated during the operation of the ozone production process. The backwash cycle process is: the backwash electric valve is controlled to open, and the ozone micro-nano bubble water flows into the backwash pipeline and passes through the ceramic membrane filter. Then it enters the rear water purification port and reversely passes through the hollow nanofiltration membrane tube to complete the backwash sterilization and disinfection of the hollow nanofiltration membrane tube. The backwash water flows out through the circulating water outlet of the nanofiltration membrane device and finally flows into the water production circulation pipeline through the water production circulation electric valve, and then re-enters the water purification tank to form a backwash circulation system.

10. The control method of the integrated device for direct drinking water from nanofiltration pipeline with zero wastewater discharge according to claim 9 is characterized in that: The information of the rising or falling liquid levels in the first and second clean water tanks is fed back to the controller for adjusting the operation of the system. When the first clean water tank drops from the high liquid level to the middle liquid level, the raw water electric valve opens and the first clean water tank is replenished with water; when the liquid level in the first clean water tank drops to the low liquid level, the clean water pump stops working and the first clean water tank no longer discharges water; when the second clean water tank drops from the high liquid level to the middle liquid level, the clean water electric valve opens, and the clean water pump starts working to replenish water to the second clean water tank; when the liquid level in the second clean water tank rises to the high liquid level, the clean water electric valve closes, and the clean water pump stops working; when the liquid level drops below the middle liquid level in the second clean water tank, the clean water booster pump stops working. When the second clean water tank rises to the middle liquid level again, the controller allows the clean water booster pump to start supplying water. When the liquid level in the second clean water tank rises to the high liquid level, the water purification and production work is completed.

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