Vertical pressurized immersion membrane filtration system

A vertical pressurized immersion membrane filtration system includes at least one pressure vessel/tank and at least one layer of membrane modules sealed therein. Every layer has at least two parallel membrane modules, with space left between the membrane module and the pressure vessel/tank. The upper and lower ends of every membrane module have plates and the upper and lower membrane modules are hermetically connected. The plates separate the space in the pressure vessel/tank into two sealed end compartments and a middle compartment. The membrane module includes interior membrane fibers and an outer perforated supporting cylinder surrounding the membrane fibers. The pressure vessel/tank has end and middle water inlets/outlets. The pressure vessel/tanks are parallel. The multiple membrane modules work simultaneously, effectively increasing filtration efficiency. The filtration system can work in multiple operation modes, improving applicability thereof.

TECHNICAL FIELD OF THE INVENTION

The present invention relates to a membrane filtration system, specifically relates to a vertical pressurized immersion membrane filtration system.

BACKGROUND OF THE INVENTION

Nowadays, the convectional vertical pressurized membrane filtration systems are generally composed of a hollow fiber membrane modules provided in a vessel/tank, feed-water inlet pipes (manifolds and branch pipes), permeate outlet pipes (manifolds and branch pipes), concentrate pipes (manifolds and branch pipes) and a membrane rack. The membrane modules are connected in parallel on the two sides of the manifolds. Because of the limited filtration capacity of a single membrane module, the large system needs to use many membrane modules, which leads to system complexity, high cost and risk of fault. Furthermore the convectional pressurized membrane filtration system is not compatible with an immersion membrane filtration system.

CONTENT OF THE INVENTION

The purpose of the present invention is to solve the deficiency/problems of existing conventional technology. The present invention provides a vertical pressurized immersion membrane filtration system with simple structure and low cost, which can be provided with one layer or two layers of membrane modules and multiple membrane modules working simultaneously in one pressure vessel/tank, and that effectively increases filtration efficiency of the filtration system. The present invention can work in multiple operation modes, which extremely improves the applicability.

The present invention provides a vertical pressurized immersion membrane filtration system, which includes a vertically-set pressure vessel/tank with its ends sealed, and at least one layer of membrane module sealed in said pressure vessel/tank, every layer is provided with at least two membrane modules, and the membrane modules in every layer are in parallel to each other; there is a clearance between the said membrane module and said pressure vessel/tank. End plates are provided on the uppermost end and the lowest end of the membrane modules, and the said two end plates separate the space in the pressure vessel/tank into two end compartments which is respectively sealed and a middle compartment in between the end plates vessel/tank. The said membrane modules include membrane fiber and an outer perforated supporting cylinder, the water passes in or out of said perforated supporting cylinder. The said pressure vessel/tank is provided with an end water inlets/outlets respectively at the outsides of both of the two end compartments, the said vessel/tank is provided with a middle water inlets/outlets at the outside of said middle compartment. The multiple pressure vessel/tanks are provided in parallel to each other for large filtration system.

The vertical pressurized immersion membrane filtration system of the present invention also can be:

Two layers of membrane modules are sealed in said pressure vessel/tank, and the adjacent membrane modules between two layers are hermetically connected by connectors.

The upper and lower ends of the pressure vessel/tank are provided with a detachable upper and lower cover respectively for sealing said pressure vessel/tank.

Said membrane module includes potting located at the two ends of the membrane fibers, and ending heads located at the outside of said potting. Said ending heads fix said potting, said membrane fibers and said outer perforated supporting cylinder together.

Said end plates are provided with fixing holes with their shape being match up with the shape of said ending heads. The edge of the upper ending heads located at the upper end of said membrane module are hermetically fixed in the fixing holes of the upper end plate. The edge of the lower ending heads located at the lower end of said membrane module are hermetically fixed in the fixing holes of the lower end plate.

The size of the fixing holes on the upper end plate is bigger than the size of the fixing holes on the lower end plate. The fixing hole of the upper end plate is fixed with the outer wall of the upper ending head on the upper end of said membrane module. The fixing hole of the lower end plate is fixed with the inner wall of the lower ending head on the lower end of said membrane modules.

The shape of said ending head, potting, outer perforated supporting cylinder and said fixing holes are coincident.

Said outer perforated supporting cylinder can be of net-shaped sheet or cylinder with water-flow-through holes.

Said pressure vessel/tank is made of metallic material, or concrete material.

Said pressure vessel/tank is built on the ground or the lower half part of said pressure vessel/tank is located under the ground.

Said two end water inlet/outlets are located at the same side of said pressure vessel/tank.

Said two end water inlet/outlets and said middle inlet/outlet are located at the same side of said pressure vessel/tank.

Said middle water inlet/outlet is located at the highest point of said middle compartment.

The vertical pressurized immersion membrane filtration system in the present invention, includes a vertically-set pressure vessel/tank with its end sealed, and at least one layer of membrane modules, which is provided and sealed in said pressure vessel/tank. Every layer of membrane modules provided with at least two membrane modules, and the membrane modules in each layer of membrane module are in parallel to each other. There is clearance between said membrane modules in said pressure vessel/tank. The end plates are provided on the uppermost end and the lowest end of said membrane modules, and said two end plates separate the space in the pressure vessel/tank into two sealed end compartments which is respectively sealed and a middle compartment between the two end compartments. The two end compartments are located respectively at the upper end and lower end of the pressure vessel/tank, the said membrane modules include membrane fiber and an outer perforated supporting cylinder, the water passes in or out of said perforated supporting cylinder, said pressure vessel/tank is provided with end inlets/outlets respectively at the outside of both two end compartments, said pressure vessel/tank is also provided with a middle inlet/outlet at the outside of the middle compartment, the pressure vessel/tanks are provided in parallel to each other. Compared with current technology, the vertical pressurized immersion membrane filtration system of present invention has advantages such as: the membrane fibers are surrounded by a permeable outer perforated supporting cylinder. The feed-water can either enter into the membrane lumens from two ends of the membrane modules and then discharged from the circumference of the membrane module, or the feed—water can be distributed in the membrane bundles and be filtrated through from outer of the membrane fibers and the permeate come out from two ends of the membrane modules, namely both inside-out membrane and outside-in membrane can be used for the same pressure vessel/tank, which extends the applicability of the membrane filtration system. Moreover, since one or two layers of membrane modules can be loaded and each layer of the membrane module is composed of at least two membrane modules, multiple membrane modules can be provided in one pressure vessel/tank, and the multiple membrane modules work on filtrating water simultaneously, which improves extremely the filtration efficiency of the filtration system. Furthermore, every membrane module is sealed on the end plates, it is not necessary to replace all of the membrane modules in the maintenance procedure, and only the one with deficiency needs to be replaced or repaired, which is convenient for maintenance and thus prolongs the lifecycle of the whole membrane filtration system. At the same time, the simple structure of the membrane modules and the end plates enables easy fabrication and reduces largely the manufacturing cost of the overall vertical pressurized immersion membrane filtration system. Further more, multiple pressure vessel/tanks can be installed for filtration together, which further improves the filtration efficiency.

ILLUSTRATION OF THE REFERENCE NUMBERS IN FIGURES

DETAILED DESCRIPTION OF THE INVENTION

The First Embodiment

Referring to theFIG. 1toFIG. 11, the vertical pressurized immersion membrane filtration system of the present invention, includes at least one vertically-set pressure vessel/tank1with its ends being sealed, and at least one layer of membrane module, being sealed provided in said pressure vessel/tank1, at least two vertically—set membrane modules2are provided in every layer of membrane module, the membrane modules2in every layer of membrane modules are in parallel with each other, there is a clearance3between said membrane module and said pressure vessel/tank1, the uppermost and lowest ends of said every line of membrane module are provided with end plates6, said two end plates6separate the space in the pressure vessel/tank2into two sealed end compartments8and a middle compartment9, the two end compartments8are thus at the upper and lower ends of the pressure vessel/tank1, and the middle compartment9is between said two end compartments8. Said membrane module2includes interior membrane fibers10and an outer perforated supporting cylinder which surrounds the exterior of the membrane fibers10, the water passes in or out of said outer perforated supporting cylinder, said pressure vessel/tank1is provided with an end water inlet/outlet13respectively at the outside of both two end compartments8, said pressure vessel/tank1is also provided with a middle water inlet/outlet14at the outside of the middle compartment9, the pressure vessel/tanks1are provided in parallel with each other. The further preferred technical proposal is that the upper and lower membrane modules2in said two layers of membrane modules are hermetically connected by a connector7, i.e. add one layer of membrane module. It can improve the filtration efficiency. The details of the operation modes of the vertical pressurized immersion membrane filtration system are as follows:

A. Dead-end, inside-out filtration: as shown inFIG. 1, in the stage of filtration, raw water enters into the two end compartments8via the two end water inlet/outlets13located at the outside of the two end compartments8. Under pressure, the water enters into the lumens of the membrane modules2via the end holes of the membrane fibers10of the membrane modules2which is connected with the end compartments8, then under pressure, the water filtrates through membrane matrix and passes out of the outer perforated supporting cylinder of the membrane modules2. And most of the filtrated water is collected between the pressure vessel/tank1and the membrane fibers10, the rest flows through the membrane modules2and be filtrated via membrane fibers10on the membrane modules2which is located at the edge. And after filtration by the membrane fibers10in the membrane modules2, the water flows out of the outer perforated supporting cylinder and enters into the middle compartment9, and then the filtrated water is discharged from the middle water inlet outlet14under pressure. In the stage of cleaning, the clean water enters into the middle compartment9from the middle water inlet outlet, then it enters into the interior of the membrane modules2in opposite direction under pressure, namely it enters into the interior of the membrane fibers10and cleans up the pollutions on the inner surface of the membrane fibers10, and then the backwash water and the pollutions are discharged into the end compartments8from the ends of the membrane fibers10and the membrane modules2, then they are discharged out of the pressure vessel/tank1under pressure. The membrane modules2and the pressure vessel/tank1are thus cleaned up so that the system can go on with the next filtration procedure. As shown inFIG. 4, two layers of the membrane modules are provided in the pressure vessel/tank1, the upper and lower membrane modules2of the two layers of the membrane modules are hermetically connected by the connectors7to ensure that the water can be directly carried and filtrated in the membrane modules2and avoiding blending with the water in the middle compartment. In the embodiment shown inFIG. 4, when it is filtrated, the water coming from the two ends of the pressure vessel/tank1and entering into one membrane module thus enters another membrane module2by going through the connector to be filtrated, which further improves the filtration efficiency.

B. Dead-end, outside-in filtration: as shown inFIG. 2, the raw water enters into the middle compartment9of the pressure vessel/tank1from the middle water inlet outlet14, then it infiltrates into the membrane fibers10of the membrane modules2to be filtrated, then is discharged into the end compartments8through the membrane modules2which are connected with the end compartments8, and then the filtrated water is discharged via the end water inlets/outlets13under pressure. In the stage of cleaning, the cleaning water enters into the end compartments8of the pressure vessel/tank1from the end water inlet outlets13, then it flows from the ends of the membrane modules2into the membrane fibers10of the membrane modules2to clean the surface of the membrane fibers10, and the polluted water and the pollutions are discharged from the middle water inlet outlet14, the membrane modules2and the pressure vessel/tank1are thus cleaned up.

C. Cross-flow, inside-out filtration: as shown inFIG. 3, in the stage of filtration, the raw water enters into the lower end compartment8in the pressure vessel/tank1from the lower end water inlet outlet13. Part of the raw water enters into the membrane fibers10to be filtrated via the membrane modules2which are connected with the lower end compartment8, and some of the raw water goes through the membrane modules2and directly enters into the next membrane modules2to go on with filtration, the rest of the raw water enters into the membrane module2and is discharged into the upper end compartment8and then is discharged via the upper end water inlet outlet13(i.e. concentrate outlet), and then after being filtrated by the membrane fibers10in the membrane modules2, the filtrated water flows out of the outer perforated supporting cylinder and enters into the middle compartment9, and is discharged from the middle water inlet outlet14under pressure. In the stage of cleaning, it goes on cleaning in the opposite direction, namely the cleaning water enters into the middle compartment9of the pressure vessel/tank1from the middle water inlet/outlet14to clean the surface of the membrane modules2and infiltrate into the membrane fibers10, and under pressure, it passes out of the ends of the membrane fibers10or it infiltrates into the delivery pipe to clean the pollutions on the surface of the membrane fibers10and is discharged from the ends of the membrane modules2into the end compartments8, and is discharged from the end water inlet outlets13under pressure to achieve the purpose of further cleaning the membrane modules2and the filtration system.

Therefore, Compared with the existing technology, the vertical pressurized immersion membrane filtration system with the above described structures has the following advantages: the outer perforated supporting cylinder surrounding the outside of the membrane fibers10of the membrane module2allow water pass-through, i.e. not only the water can enters into the membrane fibers10from the two ends of the membrane modules2to be filtrated and then discharged from the outside of the membrane modules2, but also the water can be filtrated from the outside of the membrane modules2and carried to the two ends of the membrane modules2and then discharged out, namely both the internal pressure membranes and the external pressure membranes can be uses here in the present invention, which improves the applicability of the membrane filtration system. Moreover, because one layer or two layers of membrane modules can be loaded and each layer of membrane module can be composed of at least two membrane modules2, therefore, multiple membrane modules2can be provided in the pressure vessel/tank1, the multiple membrane modules2filtrate simultaneously the water, which extremely improves the filtration efficiency. Further more, every membrane module is sealed provided on the end plates6, it is not necessary to replace all of the membrane modules2, but just replace the damaged membrane2, which is convenient for repairing and it can prolong the operation life of the whole membrane filtration system. At the same time, for the simple structure of the membrane modules2and the end plates6, the production is more easily, the factory cost of the whole upright pressure infiltration compound membrane filtration system can be extremely reduced. Further more, multiple pressure vessel/tanks1can be provided in parallel and they can simultaneously go on with filtration, which further improves the filtration efficiency. The upright pressure infiltration compound membrane filtration system can be operated in the manner of the pressure type, namely increases the pressure when water infiltrates in to cause the high pressured infiltrating water, besides can be operated in the manner of immersion type, namely the water flows into the pressure vessel/tank1, and goes on with filtration by increasing the pressure by suction of the production pump. When the infiltrated water is activated sludge mixture liquid, the system can be operated in the manner of the MBR (namely membrane Bio-reactor).

The Second Embodiment

Referring toFIG. 1toFIG. 11, the vertical pressurized immersion membrane filtration system of this present, on the basis of the first embodiment, also can be that the upper and lower ends of said pressure vessel/tank1respectively are provided with an upper cover4and a lower cover5which detachably seal said pressure vessel/tank1. The advantage of providing the upper cover4and the lower cover5is sealing the pressure vessel/tank1. And the upper cover4and the lower cover5can be opened during repairing, which is convenient for repairing and maintenance. Certainly, it can only be provided with the upper cover4and the bottom of the pressure vessel/tank is sealed. The pressure vessel/tank1can be a pool poured by concrete, also can be other sealed vessel/tank. The upper part of it just can be opened so that the membrane modules2and the end plates6can be fixed. In additionally, the multiple pressure vessel/tanks can be connected, for example, two vessel/tanks or four vessel/tanks or more vessel/tanks being connected so as to make up a large filtration system. And one layer of the membrane module includes at least two membrane modules2, generally includes three, four to seven membrane modules2, the large one can include thirty membrane modules. Moreover, said outer perforated supporting cylinder includes an outer surface supporting web or an outer surface supporting frame, as long as the water filtrated by the membrane fibers10just can be exuded and the membrane fibers10can be fixed.

The Third Embodiment

Referring toFIG. 1toFIG. 11, the vertical pressurized immersion membrane filtration system of the present invention, on the basis of the first or the second embodiment, also can be that said membrane module2also includes a potting15located at the two ends of the membrane fibers10and an ending head16located outside of said potting15. Said potting15are provided at the ends of the membrane fibers10. Said ending heads16fix said potting15, said membrane fibers10and said outer perforated supporting cylinder together, so that such kind of membrane modules2can achieve the situation in which both the internal pressure infiltrating and the external pressure infiltrating can be applied in, which improves the applicability of the membrane filtration system. Certainly, the membrane modules2can have any other structures, as long as the outer of the membrane modules2infiltrating water. The further preferred technical proposal is that said end plates6is provided with fixing holes12which have the shape being in conformity with the shape of said ending heads16. The edge of the upper ending head16located at the upper ends of said membrane modules2is hermetically fixed in the fixing holes12of the upper end plate16. The edge of the lower ending heads16located at the lower end of said membrane modules2is hermetically fixed in the fixing holes12of the lower end plate6. In this way, the membrane modules2are sealed fixed in the middle compartment9so that the water in the end compartments8and the water in the middle compartment9aren't blended together to affect the filtration result. The further preferred technical proposal is that the size of the fixing holes12on the upper end plate6is bigger than the size of the fixing holes12on the lower end plate6. The fixing holes on said upper end plate6are fixed with the outer wall of said upper ending head16on the upper end of said membrane modules2. The fixing holes of said lower end plate6are fixed with the inner wall of the lower ending head16on the lower end of said membrane modules2. The advantage of such is the arrangement is that the size of the lower fixing holes is smaller than the size of the lower ending heads of the membrane modules2, which can effectively support the membrane module without providing an extra fixing device. In additionally, the shape of said potting15and said ending heads16, said outer perforated supporting cylinder and said fixing holes12are in conformity. In this way, it ensures that the end plates6hermetically fix the edge of the membrane modules2inside the middle compartment9. The further preferred technical proposal is that the shape of said potting15, said end heads16, the said outer perforated supporting cylinder and the fixing holes12all being square or round. In this way, the manufacturing process is simple and the cost is low.

Referring toFIG. 1toFIG. 11, the vertical pressurized immersion membrane filtration system of the present invention, on the basis of the first or second or third or forth embodiment, also can be that said outer perforated supporting cylinder11includes an outer surface supporting web or an outer surface supporting frame. In which, if the outer contour shape of the membrane modules2is round, then the outer perforated supporting cylinder11is a supporting web surrounding the outer of the membrane modules2. And if the outer contour shape of the membrane modules2is square, then the outer perforated supporting cylinder11is a supporting frame which is located at the four edges for fixing and supporting. Certainly, the outer perforated supporting cylinder11can be any other types, as long as it can support and fix the membrane modules2. In additionally, said pressure vessel/tank1is made of the metallic material or concrete material. The advantage of the pressure vessel/tank1being made of the metallic material is the convenient for fixing and good sealing ability, the advantage of the pressure vessel/tank1being made of concrete material is the low cost and the little corroding effects by the rain and air. In additionally, said pressure vessel/tank1can be built on the ground or the lower half part of said pressure vessel/tank1located under the ground, thus the half part of the pressure vessel/tank1buried under the ground can reduce the lifting capability of the system and extremely save the energy consumption.

The Forth Embodiment

Referring toFIG. 1toFIG. 11, the vertical pressurized immersion membrane filtration system of the present invention, on the basis of the first or second or third embodiment, also can be that said two end water inlet outlets are respectively provided at the same side of said pressure vessel/tank1. In this way, the advantage is that the configuration of the pipeline is convenient, the pipeline is simply and the cost can be reduced. The further preferred technical proposal is that said two end water inlet outlets and said middle water inlet outlet14are all provided at the same side of said pressure vessel/tank1respectively. In this way, the advantage is that the configuration of the pipeline is convenient, the pipeline is simply and the cost can be reduced. The most preferred technical proposal is that said pressure vessel/tank1is built on the ground or the lower half part of said pressure vessel/tank1is located under the ground.

The above stated is only a few embodiments of the present invention, and does not limit the protect field of the present invention. Any equal changes and modifications made according to the technical spirit of the present invention belong to the scope of the technical solution of the present invention.