MBR (Membrane Bioreactor) membrane system with pulse cleaning and dosing device

Abstract

The utility model discloses an MBR (Membrane Biological Reactor) membrane system with a pulse cleaning and dosing device, which comprises a water producing tank, a membrane tank, a membrane module arranged in the membrane tank and a dosing device, the membrane module is connected with the water producing tank through a water producing pump and a water producing pipeline, and a water producing automatic valve is arranged on the water producing pipeline at the inlet of the water producing pump. The water producing tank is connected with the membrane module device through a backwashing pump and a backwashing pipeline; a pipeline mixer and a backwashing automatic valve are arranged on the backwashing pipeline at the outlet of the backwashing pump; the alkali washing dosing device is connected with the pipeline mixer through an alkaline dosing pipe, and the acid washing dosing device is connected with the pipeline mixer through an acidic dosing pipe. According to the invention, backwashing and cleaning share one set of device, so that the arrangement of pumps, instruments and automatic valves is reduced, the arrangement of self-control point positions is reduced, the operation stability of the self-control system is improved, and meanwhile, a better cleaning effect can be obtained in a shorter time by using a pulse type dosing mode with lower chemical consumption.

Description

Technical Field

[0001] The utility model relates to the technical field of sewage treatment, in particular to an MBR membrane system provided with a pulse cleaning and dosing device. Background Art

[0002] MBR membrane systems are widely used in the construction, renovation or expansion of sewage treatment plants and small and medium-sized integrated sewage treatment equipment due to their excellent and stable effluent quality, small footprint, strong anti-pollution ability and easy maintenance. There are two existing cleaning methods for MBR membrane systems: one is to dosing through continuous backwashing, and the other is to dosing directly into the membrane tank. The direct dosing cleaning method consumes a lot of chemicals, and the water pipes and membrane fibers are difficult to clean. The continuous backwashing and dosing cleaning method usually requires a separate cleaning pump, with complex equipment and piping configurations and many control points. In addition, the water tanks, membrane tanks and dosing devices of existing membrane systems are usually dispersed, occupying a large area, and are not suitable for the renovation and expansion of various sewage treatment projects. In addition, the water replenishment of existing dosing devices is usually pumped to the dosing storage tank with tap water or a newly added water replenishment pump, resulting in waste of water resources and power. Summary of the Invention

[0003] In order to solve the above problems, the utility model provides an MBR membrane system provided with a pulse cleaning and dosing device.

[0004] The technical solution adopted in this utility model is:

[0005] The MBR membrane system is provided with a pulse cleaning and dosing device, comprising a water production tank, a membrane tank, a membrane module arranged in the membrane tank, and a dosing device. The water production tank is arranged on the side of the membrane tank, an installation space is provided below the water production tank, and the dosing device is arranged in the installation space; the membrane module is connected to the water production tank through a water production pump and a water production pipeline, the water production pipeline at the water production pump inlet is provided with a water production automatic valve, the water production tank is connected to the membrane module through a backwash pump and a backwash pipeline, the backwash pipeline at the backwash pump outlet is provided with a pipeline mixer and a backwash automatic valve, the backwash automatic valve outlet is connected to the water production automatic valve inlet, and the water production automatic valve inlet is connected to the water production port of the membrane module; the dosing device comprises an alkali wash dosing device and an acid wash dosing device, the alkali wash dosing device is connected to the pipeline mixer through an alkaline dosing pipe to provide alkaline backwashing agent for the membrane module, and the acid wash dosing device is connected to the pipeline mixer through an acidic dosing pipe to provide acidic backwashing agent for the membrane module.

[0006] Furthermore, a backwash flow meter is provided on the backwash pipeline, which is located between the backwash pump and the pipeline mixer. It is used to monitor the backwash water volume and ensure that the backwash water is 20-30L / (m 2h) high-flux flushing of the membrane fibers. The reagent enters from the outlet end of the membrane (i.e., the water production end) and flows through the membrane fibers to the inlet end (i.e., the raw water end). It fully contacts the membrane fiber pores and membrane fiber surfaces, increasing the contact area between pollutants and the reagent. This reverse flow helps loosen and flush away dirt and sediment attached to the membrane fibers, enhancing the cleaning effect.

[0007] Furthermore, the water pipe at the water pump outlet is connected to the water production pool through a bell mouth. The bell mouth controls and adjusts the water level, increases the contact area of ​​the water outlet, reduces the water outlet pressure, and prevents excessive water pressure from impacting the pool top.

[0008] Furthermore, a pressure transmitter is installed on the water production pipeline, which is located between the membrane module and the water production automatic valve to monitor the system's water production transmembrane pressure difference, including the safe operation of the membrane.

[0009] Furthermore, the alkaline washing dosing device includes an alkaline dosing tank, an alkaline dosing pump and an alkaline dosing automatic valve connected in sequence through an alkaline dosing pipe. The alkaline dosing tank is connected to the water production pool through an alkaline dosing water replenishment pipe, and an alkaline dosing water replenishment automatic valve is provided on the alkaline dosing water replenishment pipe.

[0010] With the above technical solution, the water for dosing comes from the system's produced water and flows to the dosing tank by gravity, saving power and water resources and realizing sewage recycling.

[0011] Furthermore, the alkaline dosing tank is provided with an alkaline agent level gauge.

[0012] Furthermore, the pickling dosing device includes an acid dosing tank, an acid dosing pump and an acid dosing automatic valve connected in sequence through an acid dosing pipe. The acid dosing tank is connected to the water production pool through an acid dosing water supply pipe, and an acid dosing water supply automatic valve is provided on the acid dosing water supply pipe.

[0013] With the above technical solution, the water for dosing comes from the system's produced water and flows to the dosing tank by gravity, saving power and water resources and realizing sewage recycling.

[0014] Furthermore, the acid dosing tank is provided with a pickling agent level gauge.

[0015] Beneficial effects of the utility model:

[0016] 1. This application saves construction costs, operating costs, and land occupation by centrally setting up the membrane pool, water production pool, and dosing device, thereby reducing the total cost of the system.

[0017] 2. The backwashing and cleaning of this application share a set of devices, which reduces the settings of pumps, instruments and automatic valves, reduces the settings of automatic control points, and improves the operating stability of the automatic control system.

[0018] 3. This application sets up a pipeline mixer, an automatic water production valve, and an automatic backwash valve. The cleaning agent can enter the membrane wire through the backwash pump, flushing the inside of the membrane wire at high speed to improve the flushing effect. At the same time, a better cleaning effect can be achieved with less drug consumption and a shorter time through pulse dosing. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a front view of the MBR membrane system of Example 1.

[0020] Figure 2 This is a reverse view of the MBR membrane system of Example 1.

[0021] Figure 3 yes Figure 2 Top view of the water production pool removed.

[0022] In the figure: 1 water production tank, 2 first backwash pipe, 3 backwash pump, 4 backwash flowmeter, 5 pipeline mixer, 6 backwash automatic valve, 7 membrane module, 8 membrane tank, 9 first water production pipe, 10 pressure transmitter, 11 water production automatic valve, 12 water production pump, 13 bell mouth, 14 chemical platform, 2-1 alkaline dosing tank, 2-2 alkaline dosing pump, 2-3 alkaline washing chemical level gauge, 2-4 alkaline dosing automatic valve, 2-5 alkaline dosing pipe, 2-6 alkaline dosing water replenishment automatic valve, 2-7 alkaline dosing water replenishment pipe, 3-1 acid dosing tank, 3-2 acid dosing pump, 3-3 acid washing chemical level gauge, 3-4 acid dosing automatic valve, 3-5 acid dosing pipe, 3-6 acid dosing water replenishment automatic valve, 3-7 acid dosing water replenishment pipe. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings and a preferred embodiment. Example

[0024] See Figure 1-Figure 3 This embodiment provides an MBR membrane system equipped with a pulse cleaning and dosing device, including a water production tank 1, a membrane tank 8, a membrane module 7, an acid cleaning and dosing device, an alkaline cleaning and dosing device and a reagent platform 14.

[0025] Water production tank 1 is located on the side of membrane tank 8. Below this tank is an installation space, within which the dosing device is located. In practice, water production tank 1 can be constructed using a lightweight structure such as reinforced concrete or steel, forming a double-layer structure. The upper layer is used to store water, while the lower layer houses the dosing device. The lower layer can be a closed structure with a door or an open installation space, installed below the side of the membrane tank.

[0026] The membrane module 7 is arranged in the membrane pool 8 and can be arranged in parallel in multiple numbers.

[0027] The membrane module 7 is connected to the water production tank 1 via a water production pump 12 and a water production pipeline. The water production pump 12 is installed below the water production tank 1. Its inlet is connected to the water outlet of the membrane module 7 through a first water production pipe 9. The first water production pipe 9 is equipped with an automatic water production valve 11 and a pressure transmitter 10. The pressure transmitter 10 is located near the membrane module 7. The pressure transmitter 10 is used to monitor the transmembrane pressure difference of the system's water production. The automatic water production valve 11 is used to close the water production pipeline during backwash and cleaning modes. The outlet of the water production pump 12 is connected to the water production tank 1 through a second water production pipe, which is connected to the water production tank 1 through a bell mouth 13.

[0028] The water production tank 1 is connected to the membrane module 7 via a backwash pump 3 and backwash piping. The backwash pump 3 is installed below the water production tank 1. Its inlet is connected to the water production tank 1 via a first backwash pipe 2. The outlet of the backwash pump 3 is connected to the first water production pipe 9 between the water production automatic valve 11 and the pressure transmitter 10 via a second backwash pipe. The second backwash pipe is sequentially equipped with a backwash flowmeter 4, a pipeline mixer 5, and a backwash automatic valve 6. The outlet of the backwash automatic valve 6 is connected to the inlet of the water production automatic valve 11. The water in the water production tank 1 is measured by the backwash flowmeter 4 and then pumped into the membrane module 7 via the backwash pump 3 for backwashing.

[0029] The alkali wash dosing device includes an alkali dosing tank 2-1, an alkali dosing pump 2-2, and an automatic alkali dosing valve 2-4, connected in sequence via an alkali dosing pipe 2-5. The alkali dosing tank 2-1 and the alkali dosing pump 2-2 are installed below the water production tank 1. In this embodiment, a covered dosing port is provided at the top of the alkali dosing tank 2-1 for adding reagent, which is placed on a reagent platform 14. A water refill port is provided above the alkali dosing tank 2-1, connected to the water production tank 1 via an alkali dosing water refill pipe 2-7. An automatic alkali dosing water refill valve 2-6 is installed on the alkali dosing water refill pipe 2-7. An alkali dosing water refill valve 2-6 is also installed on the alkali dosing tank 2-1. An alkali reagent level gauge 2-3 is also provided on the alkali dosing tank 2-1.

[0030] The pickling dosing system includes an acid dosing tank 3-1, an acid dosing pump 3-2, and an automatic acid dosing valve 3-4, connected in sequence via an acid dosing pipe 3-5. The acid dosing tank 3-1 and the acid dosing pump 3-2 are installed below the water production tank. In this embodiment, a covered dosing port is provided at the top of the acid dosing tank 3-1 for adding reagents. The reagents are placed on a reagent platform 14, which is located on one side of the acid dosing tank 3-1. A water inlet is provided above the acid dosing tank 3-1, connected to the water production tank 1 via an acid dosing water inlet pipe 3-7. An automatic acid dosing water inlet valve 3-6 is installed on the acid dosing water inlet pipe 3-7. A pickling reagent level gauge 3-3 is also provided on the acid dosing tank 3-1.

[0031] Preferably, the water production pump 12 and backwash pump 3 are variable frequency centrifugal pumps, while the alkaline dosing pump 2-2 and acidic dosing pump 3-2 are metering pumps. The pipeline mixer 5 is made of a material that is resistant to both acid and alkali. The backwash flowmeter 4 is an electromagnetic flowmeter. The alkaline dosing tank 2-1 and acidic dosing tank 3-1 are made of PE, PP, or FRP. The alkaline agent level gauge 2-3 and the pickling agent level gauge 3-3 are magnetic flap level gauges or submersible level gauges.

[0032] The working mode of the utility model is:

[0033] When the membrane system is in operation mode, it operates in a mode of producing water for 8-12 minutes and backwashing for 20-40 seconds.

[0034] In the water production mode, the backwash pump 3 stops running, the backwash automatic valve 6 is closed, the water production automatic valve 11 is opened, and the water production pump 12 is started. When the water production pump 12 starts working, the air inside the pump and the pipeline is extracted, forming a negative pressure at the end, and the water filtered and purified by the MBR is sucked into the pump through suction, and then pumped to the water production pool 1 above.

[0035] Backwashing is performed after 8-12 minutes of water production;

[0036] During backwashing, the water production pump 12 stops running, the water production automatic valve 11 is closed, and the backwash automatic valve 6 is opened. When the backwash automatic valve 6 is fully opened, the backwash pump 3 is started. After the backwash pump 3 is started, the timing starts, and the backwash timing is 20-40s.

[0037] When backwashing is completed, the backwash pump 3 is turned off. After the backwash pump 3 is turned off, the backwash automatic valve 6 is closed, the water production automatic valve 11 is opened, and the water production pump 12 is started to produce water.

[0038] When the transmembrane pressure difference reaches 0.3 bar, the system executes the alkaline cleaning mode;

[0039] (1.1) First, the alkaline agent level meter 2-3 is used to determine whether the alkaline dosing tank 2-1 meets the start-up conditions of the alkaline dosing pump 2-2. If the start-up conditions are not met, the alkaline dosing water replenishment automatic valve 2-6 is opened, and the produced water flows by gravity through the alkaline dosing water replenishment pipe 2-7 to the alkaline dosing tank 2-1, and alkaline agent is added through the agent platform 14;

[0040] (1.2) When the liquid level in the alkaline dosing tank 2-1 reaches the start-up requirement, the system executes the alkaline agent cleaning mode, the water production pump 12 and the water production automatic valve 11 are closed in sequence, and the backwash automatic valve 6, backwash pump 3, alkaline dosing automatic valve 2-4, and alkaline agent dosing pump 2-2 are opened in sequence. The timing starts after the alkaline agent dosing pump 2-2 is started;

[0041] (1.3) When the alkaline agent cleaning timer reaches 1-5 minutes, turn off the alkaline agent dosing pump 2-2, the alkaline agent automatic valve 2-4, the backwash pump 3, and the backwash automatic valve 6 in sequence. Start timing after the backwash automatic valve 6 is closed. After the entire cleaning system is left to stand for 3-5 minutes, restart the alkaline cleaning step.

[0042] Depending on the membrane fouling situation, repeat steps (1.1) to (1.3) 3-5 times. The alkaline cleaning mode is completed and the membrane system resumes the operating mode, i.e., water production for 8-12 minutes and backwashing for 20-40 seconds.

[0043] After the alkaline cleaning mode is executed 5 times in a row, the system executes the acid cleaning mode:

[0044] (2.1) First, determine whether the acid dosing tank 3-1 meets the start-up conditions for the acid dosing pump 3-2 based on the acid reagent level gauge 3-3. If the start-up conditions are not met, open the acid dosing water replenishment automatic valve 3-6, and the produced water flows by gravity through the acid dosing water replenishment pipe 3-7 to the acid dosing tank 3-1, and the acid reagent is added through the reagent platform 14.

[0045] (2.2) When the liquid level in the acid dosing tank 3-1 reaches the startup requirement, the system executes the acid agent cleaning mode, closes the water production pump 12 and the water production automatic valve 11 in sequence, and opens the backwash automatic valve 6, the backwash pump 3, the acid dosing automatic valve 3-4, and the acid agent dosing pump 3-2 in sequence. The timing starts after the acid agent dosing pump 3-2 is started.

[0046] (2.3) When the acid cleaning timer reaches 1-5 minutes, turn off the acid dosing pump 3-2, the acid dosing automatic valve 3-4, the backwash pump 3, and the backwash automatic valve 6 in sequence. When the backwash automatic valve 6 is closed, start the timer. When the entire cleaning system is left to stand for 3-5 minutes, restart the acid cleaning step.

[0047] Depending on the membrane fouling situation, repeat steps (2.1) to (2.3) 3-5 times. The acid cleaning mode is completed and the membrane system resumes the operating mode, i.e., water production for 8-12 minutes and backwashing for 20-40 seconds.

[0048] By adopting a cleaning cycle of 1-5 minutes and a resting cycle of 3-5 minutes, alternating between cycles 3-5 times, the cleaning agent is periodically added, creating a pulsed dosing cleaning mode. The cleaning agent flows through the membrane filaments at a high flow rate in a very short period of time, removing dirt from the membrane filaments with a powerful flushing force, quickly restoring the membrane flux and performance, and improving cleaning efficiency. After cleaning, the membrane is allowed to rest, and no cleaning agent is required during the resting phase, reducing the amount of agent added during the cleaning process.

[0049] During the cleaning phase, the agent is heated at a rate of 20-30 L / (m 2h) high-flux flushing membrane fibers, entering from the outlet end of the membrane (i.e., the usual water production end), flowing through the membrane fibers toward the inlet end (i.e., the raw water end), fully contacting the membrane fiber pores and membrane fiber surfaces, increasing the contact area between pollutants and the reagent. This reverse flow helps loosen and flush away dirt and sediment attached to the membrane fibers, enhancing the cleaning effect.

[0050] During the resting phase, the agent remains within the membrane for a period of time, allowing it to fully contact and react with stubborn dirt on the membrane, thereby enhancing its cleaning effect. Furthermore, resting helps evenly distribute the agent within the membrane, ensuring that the entire membrane is effectively cleaned.

[0051] It is preferred to clean with alkaline agent for 1-5 minutes, let it stand for 3-5 minutes, and repeat 3-5 times. Clean with acidic agent for 1-5 minutes, let it stand for 3-5 minutes, and repeat 3-5 times.

[0052] When multiple membrane pools 8 are arranged in parallel, each membrane pool 8 is provided with one membrane module 7, or when there is one membrane pool and eight membrane modules 7 are provided in the membrane pool, when one membrane module executes the chemical cleaning mode, the other membrane modules 7 execute the operation mode. The membrane modules in the operation mode operate in a mode of producing water for 9 minutes and standing for 1 minute.

[0053] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications are also within the scope of protection of the present invention.

Claims

1. An MBR membrane system equipped with a pulse cleaning and dosing device, comprising a water production pool (1), a membrane pool (8), a membrane module (7) arranged in the membrane pool, and a dosing device, characterized in that: The water production pool (1) is arranged on the side of the membrane pool (8), an installation space is provided below the water production pool (1), and the dosing device is arranged in the installation space; The membrane module (7) is connected to the water production pool (1) through a water production pump (12) and a water production pipeline. The water production pipeline at the inlet of the water production pump (12) is provided with a water production automatic valve (11); The water production pool (1) is connected to the membrane module (7) through a backwash pump (3) and a backwash pipeline. A pipeline mixer (5) and a backwash automatic valve (6) are provided on the backwash pipeline at the outlet of the backwash pump (3). The outlet of the backwash automatic valve (6) is connected to the inlet of the water production automatic valve (11), and the inlet of the water production automatic valve (11) is connected to the water production port of the membrane module (7). The dosing device includes an alkaline dosing device and an acid dosing device. The alkaline dosing device is connected to the pipeline mixer (5) through an alkaline dosing pipe (2-5) to provide an alkaline backwash agent for the membrane module (7). The acid dosing device is connected to the pipeline mixer (5) through an acid dosing pipe (3-5) to provide an acid backwash agent for the membrane module (7).

2. The MBR membrane system provided with a pulse cleaning and dosing device according to claim 1, characterized in that: A backwash flowmeter (4) is also provided on the backwash pipeline. The backwash flowmeter (4) is located between the backwash pump (3) and the pipeline mixer (5).

3. The MBR membrane system provided with a pulse cleaning and dosing device according to claim 1, characterized in that: The water production pipeline at the outlet of the water production pump (12) is connected to the water production pool (1) through the bell mouth (13).

4. The MBR membrane system provided with a pulse cleaning and dosing device according to claim 1, characterized in that: A pressure transmitter (10) is also provided on the water production pipeline. The pressure transmitter (10) is provided between the membrane module (7) and the water production automatic valve (11).

5. The MBR membrane system provided with a pulse cleaning and dosing device according to claim 1, characterized in that: The alkaline washing dosing device comprises an alkaline dosing tank (2-1), an alkaline dosing pump (2-2), and an alkaline dosing automatic valve (2-4) which are sequentially connected via an alkaline dosing pipe (2-5); the alkaline dosing tank (2-1) is connected to a water production pool (1) via an alkaline dosing water replenishment pipe (2-7); and an alkaline dosing water replenishment automatic valve (2-6) is provided on the alkaline dosing water replenishment pipe (2-7).

6. The MBR membrane system provided with a pulse cleaning and dosing device according to claim 5, characterized in that: An alkaline agent liquid level gauge (2-3) is provided on the alkaline agent dosing tank (2-1).

7. The MBR membrane system provided with a pulse cleaning and dosing device according to claim 1, characterized in that: The pickling dosing device comprises an acid dosing tank (3-1), an acid dosing pump (3-2) and an acid dosing automatic valve (3-4) which are sequentially connected via an acid dosing pipe (3-5); the acid dosing tank (3-1) is connected to a water production pool (1) via an acid dosing water supply pipe (3-7); and an acid dosing water supply automatic valve (3-6) is provided on the acid dosing water supply pipe (3-7).

8. The MBR membrane system provided with a pulse cleaning and dosing device according to claim 7, characterized in that: A pickling agent level gauge (3-3) is provided on the acid dosing tank (3-1).

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