Ultrafiltration membrane filtration system

Abstract

The utility model relates to an ultrafiltration membrane filtration system. The filtration system comprises a water supply pump, a pre-filter, a circulating cross-flow pump and a plurality of ultrafiltration membrane filtration units, the water supply pump is connected with the pre-filter through a pipeline; a water outlet of the pre-filter is connected with a water inlet of the circulating cross-flow pump through a water supply pipeline; a water outlet of the circulating cross-flow pump is communicated with the circulating water inlet pipeline; a water inlet of the ultrafiltration membrane filtering unit is communicated with a circulating water inlet pipeline through a circulating water inlet branch; a water inlet valve is arranged on the circulating water inlet branch; a concentrated water port of the ultrafiltration membrane filtration unit is communicated with a circulation loop pipeline through a circulation recovery branch, and the circulation loop pipeline is further communicated with a water supply pipeline; a circulating valve is arranged on the circulating recovery branch; a water producing port of the ultrafiltration membrane filtering unit is communicated with a water producing pipeline through a water producing branch; the circulating water inlet branch is also communicated with a water drainage pipeline; and a backwashing valve is arranged on the water drainage pipeline. According to the scheme provided by the utility model, the performance of water production and backwashing can be improved, and the flushing structure of ultrafiltration membrane filtration is simplified.

Description

TECHNICAL FIELD

[0001] The present application relates to an ultrafiltration membrane filtration system, which is suitable for the technical field of water treatment and feed liquid separation. BACKGROUND

[0002] Ultrafiltration is a membrane separation technology. Under certain pressure, small molecule solutes and solvents can pass through a specially designed membrane with a certain pore size, while large molecule solutes cannot pass through and are left on one side of the membrane, thereby partially purifying the large molecule substances and purifying, separating or concentrating the solution. Ultrafiltration technology is mainly used to remove large molecular substances such as suspended solids, colloids, particles, bacteria and viruses in water.

[0003] Ultrafiltration membranes can be divided into organic membranes and inorganic membranes according to the membrane material, and can be divided into flat plate type, tube type, capillary type, hollow fiber type and porous type according to the external shape of the membrane.

[0004] During the ultrafiltration process, the impurities that are intercepted continuously accumulate on the membrane surface, which can affect the filtration efficiency of the ultrafiltration membrane, cause performance degradation, and even cause concentration polarization phenomenon. Therefore, an ultrafiltration process is usually matched with a backwashing system, that is, a certain amount of water flow in the direction opposite to the water inlet is used to backwash the membrane element, so that the pollutants accumulated on the membrane surface are effectively washed out, and the filtration performance of the ultrafiltration membrane is restored.

[0005] The existing backwashing system is generally provided with a backwashing water tank, a backwashing pump, a backwashing filter and a matched backwashing pipeline and valves. The backwashing water tank is used to store enough ultrafiltration water for backwashing. During backwashing, the ultrafiltration system stops producing water. Through the start of the backwashing pump and the switching of the pipeline valves, the backwashing water is transported to the water production side of the ultrafiltration membrane by the backwashing pump through the backwashing pipeline. The backwashing pump provides a set pressure and flow rate to backwash the ultrafiltration membrane system and restore the performance of the ultrafiltration membrane. After backwashing, the ultrafiltration device produces water again. The ultrafiltration water may enter mechanical impurities or precipitate particulate matter during storage, maintenance and operation. The function of the backwashing filter is to remove large particles in the backwashing water that may cause blockage of the water production side of the ultrafiltration membrane.

[0006] Although the existing ultrafiltration technology can be stably operated under the conditions of reasonable design, proper application, timely and effective backwashing and cleaning, the existing ultrafiltration membrane technology also has the disadvantages of complex backwashing procedure, large occupation of land by the backwashing system, and easy pollution of backwashing water quality.

[0007] Therefore, there is a need for an ultrafiltration membrane filtration system in the prior art to solve the problems of the existing ultrafiltration membrane filtration system. CONTENT OF THE INVENTION

[0008] The purpose of the present application is to design an ultrafiltration membrane filtration system, which aims to solve the problem of complex flushing structure of the existing ultrafiltration membrane filtration system.

[0009] The application relates to an ultrafiltration membrane filtration system, which comprises a water supply pump, a pre-filter, a circulating cross-flow pump and a plurality of ultrafiltration membrane filtration units; the water outlet of the water supply pump is connected with the water inlet of the pre-filter through a pipeline; the water outlet of the pre-filter is connected with the water inlet of the circulating cross-flow pump through a water supply pipeline; the water outlet of the circulating cross-flow pump is communicated with a circulating water inlet pipeline; the water inlets of the ultrafiltration membrane filtration units are respectively communicated with the circulating water inlet pipeline through circulating water inlet branches; a water inlet valve is arranged on the circulating water inlet branch; the water inlet valve is used for controlling the communication between the circulating water inlet branch and the circulating water inlet pipeline; the concentrated water outlets of the ultrafiltration membrane filtration units are respectively communicated with a circulating recovery branch and a circulating loop pipeline; the circulating recovery branch is also communicated with the water supply pipeline; a circulating valve is arranged on the circulating recovery branch; the circulating valve is used for controlling the communication between the circulating recovery branch and the circulating loop pipeline; the water outlets of the ultrafiltration membrane filtration units are respectively communicated with a water outlet pipeline through water outlet branches; a water outlet valve is arranged on the water outlet pipeline; the circulating water inlet branch is also communicated with a drainage pipeline; a backwashing valve is arranged on the drainage pipeline.

[0010] In some embodiments, the circulating recovery branch is also communicated with the drainage pipeline; a drainage valve is arranged on the circulating recovery branch; the drainage valve is used for controlling the communication between the circulating recovery branch and the drainage pipeline.

[0011] In some embodiments, the circulating loop pipeline is also communicated with a concentrated water discharge pipeline; a switch valve and a concentration valve are arranged on the concentrated water discharge pipeline; the opening degree of the concentration valve can be adjusted.

[0012] In some embodiments, each ultrafiltration membrane filtration unit comprises at least one ultrafiltration membrane element; the water outlets of the ultrafiltration membrane elements are respectively communicated with the water outlet pipeline through respective water outlet branches.

[0013] In some embodiments, the water inlets of the ultrafiltration membrane elements are respectively communicated with the circulating water inlet branch through respective circulating branches.

[0014] In some embodiments, the concentrated water outlets of the ultrafiltration membrane elements are respectively communicated with the circulating recovery branch through respective concentrated water branches.

[0015] In some embodiments, the water inlets of each ultrafiltration membrane filtration unit are respectively communicated with the circulating water inlet pipeline through respective circulating water inlet branches.

[0016] In some embodiments, the circulating water inlet branch of each ultrafiltration membrane filtration unit is respectively communicated with a drainage pipeline; the circulating recovery branch of each ultrafiltration membrane filtration unit is respectively communicated with the circulating loop pipeline.

[0017] In some embodiments, the water supply pump comprises a motor; the motor is a variable frequency motor.

[0018] The ultrafiltration membrane filtration system has the following technical advantages:

[0019] (1) The ultrafiltration membrane filtration system provided by the application realizes self-backwashing by switching the operation state of multiple ultrafiltration membrane filtration units to perform forward and reverse flushing of a single set of ultrafiltration membrane filtration units, thereby canceling the backwashing system such as the backwashing water tank, backwashing water pump, backwashing filter, etc., improving the backwashing effect of the filtration system, saving equipment land occupation, and simplifying the control process.

[0020] (2) The ultrafiltration membrane filtration system provided by the application improves the water production and backwashing performance by forming high-speed cross flow of the circulating inlet water pipeline and the circulating loop pipeline through the cross flow circulating pump, thereby improving the tolerance of the membrane to pollutants. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 is a partial schematic view of an ultrafiltration membrane filtration system of the application.

[0022] Figure 2 is a schematic view of an ultrafiltration membrane filtration system of the application.

[0023] In the figure: 1, water supply pump; 2, pre-filter; 3, cross flow circulating pump; 4, ultrafiltration membrane filtration unit; 41, ultrafiltration membrane element; 5, circulating valve; 6, water inlet valve; 7, backwashing valve; 8, drain valve; 9, water production valve; 10, on-off valve; 11, concentration valve; 12, circulating inlet water pipeline; 13, circulating loop pipeline; 14, water production pipeline; 15, water production branch; 16, circulating recovery branch; 17, water production branch; 18, drain pipeline. DETAILED DESCRIPTION

[0024] To make the purpose, technical solutions and advantages of the application clearer and more apparent, the embodiments of the application will be described in detail below with reference to the drawings. It should be noted that the embodiments and features in the embodiments of the application can be combined with each other as long as they do not conflict. Those skilled in the art can understand that the ultrafiltration membrane filtration system of the application can be used in the field of water treatment.

[0025] As Figures 1-2As shown, the application provides an ultrafiltration membrane filtration system, which comprises a water supply pump 1, a pre-filter 2, a circulating cross-flow pump 3 and a plurality of ultrafiltration membrane filtration units 4. The water outlet of the water supply pump 1 is connected with the water inlet of the pre-filter 2 through a pipeline; the water outlet of the pre-filter 2 is connected with the water inlet of the circulating cross-flow pump 3 through a water supply pipeline, and the pre-filter 2 preliminarily intercepts large particles and suspended matters in the incoming water. The water outlet of the circulating cross-flow pump 3 is communicated with a circulating water inlet pipeline 12; the circulating cross-flow pump 3 provides power required by water flow scouring and cross-flow circulation of the membrane filtration unit during operation of the device. Further, the water inlets of the respective ultrafiltration membrane filtration units 4 are respectively communicated with the circulating water inlet pipeline 12 through circulating water inlet branches 17; wherein the circulating water inlet branches 17 are provided with water inlets 6, which are used to control the communication between the circulating water inlet branches 17 and the circulating water inlet pipeline 12, so that the communication between the circulating water inlet branches 17 and the circulating water inlet pipeline 12 can be cut off during backwashing. The concentrated water outlets of the respective ultrafiltration membrane filtration units 4 are respectively communicated with a circulating loop pipeline 13 through circulating recovery branches 16, and the circulating loop pipeline 13 is also communicated with the water supply pipeline to realize the backflow of the concentrated water and the secondary filtration. Further, the circulating recovery branches 16 are provided with circulating valves 5, which are used to control the communication between the circulating recovery branches 16 and the circulating loop pipeline 13, and can cut off the communication between the circulating recovery branches 16 and the circulating loop pipeline 13 during forward flushing, so that the water subjected to forward flushing in the ultrafiltration membrane filtration unit 4 can be discharged through a drain pipeline 18. Further, the water outlets of the respective ultrafiltration membrane filtration units 4 are respectively communicated with a water production pipeline 14 through water production branches 15, and the water production pipeline 14 is provided with water production valves 9. The circulating water inlet branches 17 are also communicated with the drain pipeline 18, and the drain pipeline 18 is provided with backwashing valves 7, which are in a closed state during normal water production and are in an open state during reverse flushing. The ultrafiltration membrane filtration unit 4 of the application scheme intercepts particles, suspended matters and the like in water on the concentrated water side during water production, so as to achieve the purpose of purifying water quality. After the water is circulated and concentrated, the pollutants intercepted are discharged in a forward or reverse flushing mode in a regular manner.

[0026] The utility model provides a novel ultrafiltration membrane filtration device, do not need backwashing water tank and backwashing system, through a plurality of ultrafiltration membrane filtration unit's own operation state switching, carry out single set ultrafiltration membrane filtration unit's forward and reverse flushing, pass through circulating cross-flow pump simultaneously, improve water production and backwashing's performance, simplify the flushing structure of ultrafiltration membrane filtration.

[0027] As Figure 1 And 2As shown, in some embodiments, the circulation recovery branch 16 is also connected to the drain pipe 18, and a drain valve 8 is provided on the circulation recovery branch 16. The drain valve 8 is used to control the connection between the circulation recovery branch 16 and the drain pipe 18. Specifically, before and after backwashing or during operation, the ultrafiltration membrane filter unit 4 can be flushed in both forward and reverse directions by opening the backwash valve 7 or the drain valve 8 to enhance the backwashing performance.

[0028] like Figure 1 and 2 As shown, in some embodiments, the circulation loop 13 is also connected to the concentrate discharge duct, and the concentrate discharge duct is provided with a switch valve 10 and a concentration valve 11; the opening of the concentration valve 11 can be adjusted so that a small amount of concentrate can be discharged during water production or flushing.

[0029] like Figure 1 and 2 As shown, in some embodiments, each ultrafiltration membrane filtration unit 4 includes at least one ultrafiltration membrane element 41, preferably two or three ultrafiltration membrane elements 41, and multiple ultrafiltration membrane elements 41 are arranged in parallel. The product water port of each ultrafiltration membrane element 41 is connected to the product water pipeline 14 through its own product water branch 15 to achieve self-control. In the present application, multiple ultrafiltration membrane filtration units 4 are configured in the ultrafiltration membrane filtration system. Each membrane filtration unit is composed of one or more ultrafiltration membrane elements 41, and each ultrafiltration membrane filtration unit 4 can perform forward and reverse flushing by switching the self-operating state of multiple ultrafiltration membrane filtration units to achieve the purpose of cleaning the membrane filtration unit.

[0030] like Figure 1 and 2 As shown, in some embodiments, the inlet of each ultrafiltration membrane element 41 is connected to the circulating water inlet branch 17 through its own circulation branch to achieve self-control of the water inlet and improve the water inlet efficiency.

[0031] like Figure 1 and 2 As shown, in some embodiments, the concentrate outlet of each ultrafiltration membrane element 41 is connected to the circulation recovery branch 16 through its own concentrate branch, so as to realize the self-recycling and controlled discharge of concentrate and improve efficiency.

[0032] like Figure 1 and 2 As shown, in some embodiments, the water outlet of each ultrafiltration membrane element 41 is connected to the water pipeline 14 through its own water production branch 15 to achieve self-control of water production.

[0033] like Figure 1 and 2As shown, the ultrafiltration membrane filtration unit 4 includes a plurality, preferably four or five; wherein the water inlet of each ultrafiltration membrane filtration unit 4 is respectively communicated with the circulating water inlet pipeline 12 through the respective circulating water inlet branch 17, to realize self water inlet control and improve water inlet efficiency. Further, the water outlet of each ultrafiltration membrane filtration unit 4 is respectively communicated with the water outlet pipeline 14 through the respective water outlet branch 15, to realize self water outlet control and improve water outlet efficiency. Specifically, the water outlets of the plurality of ultrafiltration membrane filtration units 4 are collected to the water outlet pipeline 14, thereby being delivered out.

[0034] As shown in Figure 1 and 2 In some embodiments, the circulating water inlet branch 17 of each ultrafiltration membrane filtration unit 4 is respectively communicated with a drainage pipeline 18, thereby realizing individual flushing discharge and improving drainage efficiency. The circulating recovery branch 16 of each ultrafiltration membrane filtration unit 4 is respectively communicated with the circulating loop pipeline 13, thereby realizing individual backflow and improving circulation efficiency.

[0035] As shown in Figure 1 and 2 In some embodiments, the water supply pump 1 includes a motor, and the motor is a variable frequency motor. Specifically, the water supply pump 1 adopts a variable frequency motor, thereby realizing variable frequency control mode, providing the water flow and pressure required in the system operation process of water production and backwashing and flushing, and being able to accurately control the operating flow and pressure during water production and backwashing, thereby improving the backwashing performance.

[0036] As shown in Figures 1-2 The present application proposes an ultrafiltration membrane filtration system, and the process thereof is as follows:

[0037] The water inlet is sucked by the water supply pump 1, enters the pre-filter 2 after being lifted in pressure by the water supply pump 1, and the water outlet of the pre-filter 2 enters the water inlet side of the circulating crossflow pump 3; the water inlet passes through the water supply pipeline, the circulating crossflow pump 3, the circulating water inlet pipeline, the ultrafiltration membrane filtration unit 4, and is concentrated, part of the concentrated liquid enters the circulating loop pipeline 13, and is discharged through the concentrated water pipeline by the concentration valve 11 and the on-off valve 10. Part of the concentrated liquid reenters the circulating water inlet pipeline 12 to continue concentration through the circulating loop pipeline 13;

[0038] When the water inlet passes through the ultrafiltration membrane filtration unit 4, the clean water permeates the ultrafiltration membrane element 41 under the pressure provided by the water supply pump 1, forms permeate, enters the water outlet pipeline, and is delivered out through the water outlet valve 9;

[0039] After a certain time of circulating concentration filtration, due to the increase of the pollutant concentration of the influent water, the pressure required for filtration increases, and the water production of the ultrafiltration membrane filtration unit 4 decreases, at which time the opening degree of the water production valve 9 needs to be closed or adjusted to reduce the water production delivery amount; meanwhile, the circulating valves 5 and 6 of one ultrafiltration membrane filtration unit 4 and the influent valve are closed, and the backwashing valve 7 in the current ultrafiltration membrane filtration unit 4 is opened, at which time the water production of the remaining ultrafiltration membrane filtration units enters the unit water production side, and under the driving of the reverse pressure, passes through the ultrafiltration membrane element 41, enters the drain pipeline 18 for discharge through the backwashing valve 7, and in the process of passing through the ultrafiltration membrane element 41, the concentrated pollutants on the surface of the ultrafiltration membrane element 41 are washed and discharged, so as to achieve the purpose of backwashing the ultrafiltration membrane filtration unit. In the process of backwashing, the circulating valve 5 can be selectively opened, the concentrated water enters the membrane element through the circulating valve 5 and is discharged through the backwashing valve 7, so as to achieve the purpose of forward flushing of the membrane element 41. After forward flushing is completed, the circulating valve 5 is closed. After a set time, the backwashing valve 7 is closed, and the drain valve 8 is opened to continue backwashing. In this process, the influent valve 6 can also be selectively opened, the concentrated water enters the membrane element through the influent valve 6 and is discharged through the drain valve 8, so as to achieve the purpose of forward flushing of the membrane element 41. After forward flushing is completed, the influent valve 6 is closed; after backwashing continues for a set time, the backwashing valve 7 and the drain valve 8 of the current ultrafiltration membrane filtration unit 4 are closed, and the circulating valve 5 and the influent valve 6 are opened to complete the backwashing of the current ultrafiltration membrane filtration unit 4. The above steps are continued to clean the other ultrafiltration membrane filtration units 4. After all the ultrafiltration membrane filtration units 4 are backwashed, the water production valve 9 is opened to re-enter the water production.

[0040] The ultrafiltration membrane filtration system disclosed in the present application has the following technical advantages:

[0041] (1) The ultrafiltration membrane filtration system disclosed in the present application switches the running state of multiple ultrafiltration membrane filtration units to realize forward and reverse flushing of a single ultrafiltration membrane filtration unit, thereby realizing self-backwashing, canceling the backwashing system such as a backwashing water tank, a backwashing water pump and a backwashing filter, improving the backwashing effect of the filtration system, saving equipment occupation and simplifying the control process.

[0042] (2) The ultrafiltration membrane filtration system disclosed in the present application forms high-speed cross flow in the circulating influent pipeline and the circulating return pipeline through the cross-flow circulating pump, improves the water production and backwashing performance, and improves the tolerance of the membrane to pollutants.

[0043] Although the embodiments disclosed in the present application are as above, the content described is only the embodiments adopted for the purpose of facilitating the understanding of the present application, and is not intended to limit the present application. Any person skilled in the art to which the present application belongs can make any modification and change in the implementation form and details without departing from the spirit and scope of the present application, but the patent protection scope of the present application shall be subject to the scope defined in the appended claims.

Claims

1. An ultrafiltration membrane filtration system, characterized in that, The filtration system includes a water supply pump (1), a pre-filter (2), a circulating cross-flow pump (3), and multiple ultrafiltration membrane filtration units (4). The outlet of the water supply pump (1) is connected to the inlet of the pre-filter (2) through a pipeline; the outlet of the pre-filter (2) is connected to the inlet of the circulating cross-flow pump (3) through a water supply pipeline. The outlet of the circulating cross-flow pump (3) is connected to the circulating water inlet pipe (12); the inlet of each of the ultrafiltration membrane filter units (4) is connected to the circulating water inlet pipe (12) through the circulating water inlet branch (17); the circulating water inlet branch (17) is provided with an inlet valve (6); the inlet valve (6) is used to control the connection between the circulating water inlet branch (17) and the circulating water inlet pipe (12); The concentrate outlet of each of the ultrafiltration membrane filtration units (4) is connected to the circulation loop pipeline (13) through the circulation recovery branch (16), and the circulation loop pipeline (13) is also connected to the water supply pipeline; the circulation recovery branch (16) is provided with a circulation valve (5); the circulation valve (5) is used to control the connection between the circulation recovery branch (16) and the circulation loop pipeline (13); Each of the ultrafiltration membrane filtration units (4) has its water outlet connected to the water supply pipeline (14) via a water supply branch (15); the water supply pipeline (14) is equipped with a water supply valve (9). The circulating water inlet branch (17) is also connected to the drain pipe (18), and the drain pipe (18) is equipped with a backwash valve (7).

2. The ultrafiltration membrane filtration system according to claim 1, characterized in that, The recycling branch (16) is also connected to the drainage pipe (18); the recycling branch (16) is also provided with a drainage valve (8); the drainage valve (8) is used to control the connection between the recycling branch (16) and the drainage pipe (18).

3. The ultrafiltration membrane filtration system according to claim 1, characterized in that, The circulation loop pipeline (13) is also connected to the concentrate discharge pipeline, which is equipped with a switch valve (10) and a concentration valve (11); the opening degree of the concentration valve (11) can be adjusted.

4. The ultrafiltration membrane filtration system according to claim 1, characterized in that, Each of the ultrafiltration membrane filtration units (4) includes at least one ultrafiltration membrane element (41); the water outlet of each ultrafiltration membrane element (41) is connected to the water outlet pipeline (14) through its respective water outlet branch (15).

5. The ultrafiltration membrane filtration system according to claim 4, characterized in that, The inlet of each of the ultrafiltration membrane elements (41) is connected to the circulating water inlet branch (17) through its respective circulation branch.

6. The ultrafiltration membrane filtration system according to claim 4, characterized in that, The concentrate outlet of each of the ultrafiltration membrane elements (41) is connected to the circulation recovery branch (16) through its respective concentrate branch.

7. The ultrafiltration membrane filtration system according to claim 4, characterized in that, The permeate outlet of each of the ultrafiltration membrane elements (41) is connected to the permeate pipeline (14) through its respective permeate branch (15).

8. The ultrafiltration membrane filtration system according to claim 1, characterized in that, The inlet of each of the ultrafiltration membrane filtration units (4) is connected to the circulating water inlet pipe (12) through its respective circulating water inlet branch (17).

9. The ultrafiltration membrane filtration system according to claim 8, characterized in that, The circulating water inlet branch (17) of each of the ultrafiltration membrane filter units (4) is connected to a drain pipe (18); the circulating recovery branch (16) of each of the ultrafiltration membrane filter units (4) is connected to the circulating loop pipe (13).

10. The ultrafiltration membrane filtration system according to any one of claims 1 to 9, characterized in that, The water supply pump (1) includes a motor, which is a variable frequency motor.

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