Ultrafiltration membrane water purification device cleaning system

Abstract

This utility model relates to the field of ultrafiltration membrane water purification devices, and more particularly to a cleaning system for ultrafiltration membrane water purification devices that simplifies the cleaning system, enabling air washing and backwashing using only an aeration blower. The system includes a filter tank, which contains a membrane tank. An ultrafiltration membrane module is installed within the membrane tank. The outlet end of the ultrafiltration membrane module is connected to the water purification tank via a first purified water pipe. The ultrafiltration membrane module is connected to the aeration blower via an aeration pipe, which is equipped with a third valve. A backwashing pipe is also included, connecting the aeration pipe and the first purified water pipe. A backwashing valve is installed on the backwashing pipe, and the backwashing valve and the third valve are connected in parallel. This utility model is particularly applicable to ultrafiltration membrane water purification devices.

Description

Technical Field

[0001] This utility model relates to the field of ultrafiltration membrane water purification devices, and in particular to a cleaning system for ultrafiltration membrane water purification devices. Background Technology

[0002] Ultrafiltration membranes are semi-permeable polymeric membranes that separate colloids or suspended particles of a certain size from a solution. Ultrafiltration membranes are generally pressure-driven, with pore sizes ranging from 1 to 100 nm, and are classified as asymmetric membranes. Currently, ultrafiltration membranes are widely used for the advanced treatment of industrial wastewater and process water, such as the concentration, purification, and separation of macromolecules in the chemical, food, and pharmaceutical industries; sterilization of biological solutions; dye separation in dyeing and printing wastewater; recovery of glycerol from petrochemical wastewater; recovery of silver from photographic chemical wastewater; and the preparation of ultrapure water. In addition, they can also be used for sludge thickening and dewatering.

[0003] Integrated water purification equipment based on ultrafiltration membrane filtration is widely used in decentralized, small-scale water supply applications. It effectively removes suspended solids, colloids, bacteria, and large organic molecules from water, providing high-quality drinking water. The specific workflow is as follows: the raw water to be filtered flows from the pretreatment tank to the membrane tank, where it is purified at the ultrafiltration membrane module. The purified water is then transported to the purification tank via the first purified water pipe from the outlet of the ultrafiltration membrane module.

[0004] Traditional ultrafiltration membrane water purification equipment requires three methods for cleaning membrane modules: external aeration, water backwashing, and chemical cleaning. The simultaneous existence of these three cleaning systems leads to equipment complexity and high costs. Furthermore, chemical cleaning not only damages the lifespan of the ultrafiltration membrane but also results in the discharge of chemical waste. Utility Model Content

[0005] The technical problem to be solved by this utility model is to provide a cleaning system for an ultrafiltration membrane water purification device that simplifies the cleaning system and can achieve corresponding external membrane aeration and internal membrane backwashing using only an aeration blower.

[0006] The technical solution adopted by this utility model to solve its technical problem is: an ultrafiltration membrane water purification device cleaning system, including a filter tank, the filter tank including a membrane tank, an ultrafiltration membrane module is installed in the membrane tank, the outlet end of the ultrafiltration membrane module is connected to the water purification tank through a first water purification pipe, the ultrafiltration membrane module is connected to the aeration blower through an aeration pipe, a third valve is installed on the aeration pipe, including a backwash pipe, the aeration pipe and the first water purification pipe are connected through a backwash pipe, a backwash valve is installed on the backwash pipe, and the backwash valve and the third valve are connected in parallel.

[0007] Furthermore, it includes a second water purification pipe, through which the first water purification pipe is connected to the water purification tank. The second water purification pipe is equipped with a second valve, which is connected in parallel with the backwash valve.

[0008] Furthermore, it includes a PLC control system, which is electrically connected to the ultrafiltration membrane module, the aeration fan, the third valve, and the backwash valve.

[0009] Furthermore, it includes a fourth valve, which is located at the bottom of the membrane tank, and the membrane tank is connected to the outside world through the fourth valve.

[0010] The beneficial effects of this invention are as follows: First, in actual use, the raw water to be filtered enters the ultrafiltration membrane module through the membrane tank. Under the pressure of the ultrafiltration membrane module, the raw water passes through the ultrafiltration membrane for filtration, and impurities in the raw water are trapped on the surface of the ultrafiltration membrane. The purified water flows out from the outlet end of the ultrafiltration membrane module. During operation, the PLC control system monitors parameters such as membrane flux and pressure of the ultrafiltration membrane in real time. When the PLC control system detects that the membrane flux of the ultrafiltration membrane drops to a set threshold, or detects that the pressure rises to a set value, it determines that the ultrafiltration membrane needs to be cleaned. Subsequently, the aeration blower is started, the third valve is opened, and the backwash valve is closed. Compressed air is delivered from the aeration blower through the third valve and the aeration pipe, and is sprayed out from the aeration head at the end of the aeration pipe. The compressed air can then perform air washing on the outer surface of the ultrafiltration membrane. After a certain period of time, the air washing is stopped. Next, the third valve is closed and the backwash valve is opened. Compressed air flows from the aeration blower through the backwash pipe, backwash valve, and the first purified water pipe to backwash the inside of the ultrafiltration membrane, flushing away contaminants on the inner surface of the membrane. This process of air washing of the outer surface of the ultrafiltration membrane and backwashing of the inner surface is repeated until the membrane flux returns to normal. The alternation of air washing and backwashing significantly improves the cleaning effect of the ultrafiltration membrane. Secondly, by installing a second purified water pipe, the separation of the functions of transporting purified water to the purified water tank and using purified water for backwashing is achieved, ensuring that the two steps of purified water storage and purified water backwashing do not interfere with each other. Thirdly, compared to existing cleaning systems, this invention eliminates the need for chemical cleaning and water backwashing systems, resulting in a simplified structure and preventing damage to the ultrafiltration membrane from chemical cleaning, thus greatly extending the service life of the ultrafiltration membrane. This invention is particularly suitable for ultrafiltration membrane water purification devices. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the connection relationship of this utility model.

[0012] The following are labeled in the diagram: Filter tank 1, First pretreatment tank 11, Second pretreatment tank 12, Membrane tank 13, Filter plate 15, Purified water tank 2, Aeration blower 3, Ultrafiltration membrane module 4, First purified water pipe 41, Second purified water pipe 42, Backwash pipe 43, Aeration pipe 44, Backwash valve 5, Second valve 6, Third valve 7, Fourth valve 8. Detailed Implementation

[0013] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0014] like Figure 1 This diagram illustrates an embodiment of the cleaning system for an ultrafiltration membrane water purification device. The filtration tank 1 consists of a first pretreatment tank 11, a second pretreatment tank 12, and a membrane tank 13, arranged from left to right. The first pretreatment tank 11 and the second pretreatment tank 12 are separated by a filter plate, and the second pretreatment tank 12 and the membrane tank 13 are also separated by a filter plate 15. Taking the second pretreatment tank 12 and the membrane tank 13 as an example, the filter plate 15 is vertically arranged, with its bottom positioned on the bottom surface of the filtration tank 1. The raw water to be filtered overflows from the second pretreatment tank 12 into the membrane tank 13 only through the top of the filter plate 15. During this overflow process, impurities in the raw water are filtered; some impurities are blocked by the filter plate 15 in the second pretreatment tank 12 and cannot overflow into the membrane tank 13. The filtration of the first pretreatment tank 11 and the second pretreatment tank 12 achieves the same effect.

[0015] After two stages of pretreatment (first pretreatment tank 11 and second pretreatment tank 12), large particulate impurities in the water overflowing into the membrane tank 13 are essentially eliminated. The impurities in the water in the membrane tank 13 are mainly suspended solids and colloids. The water in the membrane tank 13 enters from the bottom of the cylindrical ultrafiltration membrane module 4, is filtered, and then exits from the top outlet of the cylindrical ultrafiltration membrane module 4, which is connected to the first purified water pipe 41. A second purified water pipe 42 and a backwash pipe 43 are connected in parallel at the outlet of the first purified water pipe 41. Under normal filtration conditions, the backwash valve 5 and the third valve 7 are normally closed, the backwash pipe 43 is blocked, the second valve 6 is open, and the purified water is transported to the purified water tank 2 through the second valve 6 and the second purified water pipe 42.

[0016] The PLC control system monitors parameters such as membrane flux, pressure, and flow rate in real time. For example, when the PLC control system detects that the membrane flux drops to a set threshold or the pressure rises to a set value, it determines that the ultrafiltration membrane needs cleaning. Subsequently, the PLC control system closes the second valve 6 and the backwash valve 5, and turns on the aeration fan 3 and the third valve 7. Compressed air is delivered from the outlet of the aeration fan 3 to the third valve 7, then through the aeration pipe 44 to the bottom of the ultrafiltration membrane module 4, and then sprayed out from the aeration heads. The aeration heads are evenly distributed at the bottom of the ultrafiltration membrane module 4. After the compressed air passes through the aeration heads, it forms microbubbles. These microbubbles perform air washing on the membrane surface, i.e., external aeration cleaning, thus achieving a cleaning effect. After a certain period of time, the air washing is stopped, the third valve 7 and the second valve 6 are closed, and the backwash valve 5 is opened. Compressed air is delivered from the outlet of the aeration fan 3 to the backwash valve 5 and through the backwash pipe 43 to the first clean water pipe 41, thereby achieving backwashing of the inside of the ultrafiltration membrane. During backwashing, the PLC control system precisely controls the backwashing time, flow rate, and pressure to ensure the backwashing effect while avoiding excessive impact on the membrane. After backwashing for a certain period, it is stopped and backwashing valve 5 is closed. Subsequently, the third valve 7 is reopened, and the outer surface of the ultrafiltration membrane is aerated again. This alternation of air washing and backwashing greatly improves the cleaning effect of the ultrafiltration membrane. Wastewater generated after cleaning the ultrafiltration membrane module 4 can be discharged through the fourth valve 8 at the bottom of the membrane tank 13.

Claims

1. A cleaning system for an ultrafiltration membrane water purification device, comprising a filter tank (1), wherein the filter tank (1) includes a membrane tank (13), an ultrafiltration membrane module (4) is provided in the membrane tank (13), the outlet end of the ultrafiltration membrane module (4) is connected to a water purification tank (2) through a first water purification pipe (41), the ultrafiltration membrane module (4) is connected to an aeration blower (3) through an aeration pipe (44), and a third valve (7) is provided on the aeration pipe (44), characterized in that: The backwash pipe (43) is connected to the aeration pipe (44) and the first clean water pipe (41) through the backwash pipe (43). The backwash pipe (43) is equipped with a backwash valve (5), and the backwash valve (5) and the third valve (7) are connected in parallel.

2. The cleaning system for the ultrafiltration membrane water purifying device according to claim 1, characterized in that: It includes a second water purification pipe (42), the first water purification pipe (41) is connected to the water purification tank (2) through the second water purification pipe (42), the second water purification pipe (42) is equipped with a second valve (6), and the second valve (6) and the backwash valve (5) are connected in parallel.

3. The cleaning system for the ultrafiltration membrane water purifying device according to claim 1 or 2, characterized in that: It includes a PLC control system, which is electrically connected to the ultrafiltration membrane module (4), the aeration blower (3), the third valve (7) and the backwash valve (5).

4. The cleaning system for the ultrafiltration membrane water purifying device according to claim 1 or 2, characterized in that: Includes a fourth valve (8), which is located at the bottom of the membrane tank (13), and the membrane tank (13) is connected to the outside through the fourth valve (8).

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