CN109925886B

CN109925886B - Application method and device of internal pressure type hollow fiber membrane component

Info

Publication number: CN109925886B
Application number: CN201910280042.8A
Authority: CN
Inventors: 吕剑阳
Original assignee: Individual
Current assignee: Individual
Priority date: 2019-04-09
Filing date: 2019-04-09
Publication date: 2021-10-01
Anticipated expiration: 2039-04-09
Also published as: CN109925886A

Abstract

The invention relates to a method for using an internal pressure type hollow fiber membrane component and a device thereof, wherein the flow direction of feed liquid in the tube pass of the membrane component is periodically reversed, a pressure regulating valve at a filtrate outlet is additionally arranged, the pressure value at the filtrate side outlet of the membrane component is higher than the pressure value at a concentrated solution outlet of the membrane component in the membrane filtration process, and the difference value is set to be 0.02-0.08MPa, preferably 0.03-0.05. Thereby leaving the membrane near the concentrate outlet port in a back-flush condition. Furthermore, a feed concentrate outlet pressure regulating valve and a switch valve are additionally arranged. Adjusting the outlet pressure value of the concentrated solution of the feed liquid to be 0.03-0.05MPa, and fully opening the switch valve for 1-5 minutes in the middle period of each flow direction reversal cycle. The invention overcomes the defects that the conventional membrane separation device needs to stop membrane filtration and off-line cleaning, and has the advantages of simple structure, convenient use, improved membrane filtration efficiency and the like.

Description

Application method and device of internal pressure type hollow fiber membrane component

Technical Field

The invention belongs to the field of membrane separation, and relates to an internal pressure type hollow fiber membrane component, in particular to a using method and a device of the internal pressure type hollow fiber membrane component.

Background

Internal pressure hollow fiber membrane separation technology is widely used for separation and purification in chemical industry, medicine, food, beverage, water treatment and other industrial fields.

In the current general internal pressure type hollow fiber membrane component structure, the hollow fiber membrane filaments are arranged in parallel, and two ends are fixed in the shell of the membrane component by using sealing glue such as epoxy resin and the like. During membrane filtration, feed liquid enters the inside of the membrane filaments from one end of the tube pass of the membrane filaments, concentrated solution flows out of the membrane assembly from the other end of the tube pass of the membrane filaments, filtered solution permeates through the wall of the hollow fiber membrane and flows out of the membrane assembly from the shell pass of the membrane assembly, and the feed liquid flows in a single direction to complete the membrane filtration operation. In the whole tube pass flowing process, the pressure of the feed liquid side is greater than that of the filtered liquid side, and the whole hollow fiber internal pressure membrane is in a filtering state.

During the actual membrane filtration operation, the membrane flux is significantly reduced due to the occurrence of membrane fouling. Especially, when the membrane filtration technology is used for a concentrated viscous high-pollution material system such as biochemical fermentation liquor, the problem of hollow fiber membrane pollution close to an inlet is serious, the filtration efficiency of the membrane separation device is reduced, and even the membrane filtration process can not be normally carried out. The current solution is to prolong the membrane filtration time and operate inefficiently; or stopping the machine, cleaning or replacing the membrane module, and then continuing the membrane filtration operation.

Disclosure of Invention

The invention aims to provide a novel application method of an internal pressure type hollow fiber membrane component aiming at the defects of the existing application method of the internal pressure type hollow fiber membrane, which has the advantages of simultaneous online implementation of a membrane filtering process and a membrane cleaning process and has the characteristics of simplicity, convenience, practicability, high efficiency and low consumption.

The technical scheme for realizing the purpose of the invention is as follows:

a method for using internal pressure type hollow fiber membrane module includes setting outlet pressure regulating valve of filtered liquid on outlet pipeline of filtered liquid, setting pressure value of outlet on filtered liquid side of membrane module to be higher than pressure value of outlet of concentrated liquid of membrane module in membrane filtering process and setting difference value to be 0.02-0.08MPa so as to make membrane near outlet of concentrated liquid be in back flushing state.

Moreover, the flow direction of the feed liquid in the tube pass of the membrane module is periodically reversed.

Further, a concentrate outlet pressure regulating valve and an on-off valve are provided in a line of the concentrate outlet.

Further, the pressure regulating valve on the concentrate outlet line is regulated so that the concentrate outlet side pressure is 0.03 to 0.05 MPa.

And the switch valve is opened for 1-5 min in the middle period of each membrane filtration cycle, so that pulse cleaning is realized.

An internal pressure type hollow fiber membrane component device comprises a membrane component, a feed liquid tank, a pump, a pressure regulating valve and a plurality of switch valves, wherein the feed liquid tank is connected with one end of a feed pipe, the feed pipe is provided with the pump, the feed pressure regulating valve, the other end of the feed pipe is communicated and connected with one end of two branch feed pipes, the other ends of the two branch feed pipes are respectively connected with an upper port and a lower port of the membrane component, the branch feed pipe connected with the upper port is provided with a feed switch valve, the branch feed pipe connected with the lower port is provided with a lower feed switch valve, the upper port is connected with one end of an upper branch concentrated liquid pipe, the lower port is connected with one end of a lower branch concentrated liquid pipe, the upper branch concentrated liquid pipe is provided with a concentrated liquid switch valve, the lower branch concentrated liquid switch valve is arranged on the lower branch concentrated liquid pipe, and the other ends of the upper branch concentrated liquid pipe and the lower branch concentrated liquid pipe are jointly connected with a concentrated liquid main pipe, the concentrated solution main pipe is connected with the feed liquid tank, and a filtered solution outlet pressure regulating valve and a pressure gauge are arranged on an outlet pipeline of the filtered solution.

And a concentrate outlet pressure regulating valve and a pressure gauge are arranged on the concentrate header pipe.

Besides the conventional straight arrangement, the membrane component intimal threads are better in a braided three-strand weaving or spiral twisting mode. Besides the conventional length of 1 meter, the device can be lengthened to 2 meters, and the occupied area of the membrane device is reduced.

And the inlet pressure value of the tube side of the membrane component can be improved, and the membrane filtration efficiency is improved.

The invention has the advantages and beneficial effects that:

1. the invention overcomes the defects that the conventional membrane separation device needs to stop membrane filtration and off-line cleaning, and has the advantages of simple structure, convenient use, improved membrane filtration efficiency and the like.

2. The invention adjusts the side pressure of the filtered fluid to ensure that the membrane closest to the inlet end area is in a higher-pressure membrane filtration state, and the membrane closest to the outlet end area is in a back flushing state. Has the advantage that the membrane filtration process and the membrane cleaning process are carried out on line at the same time. Moreover, the effect of membrane flux recovery by backwashing is better than that of isobaric cleaning, so that the filtration efficiency of the membrane device can be improved.

Drawings

FIG. 1 is a schematic view of a first internal pressure type hollow fiber membrane module apparatus according to the present invention;

FIG. 2 is a schematic view of a second internal pressure type hollow fiber membrane module apparatus according to the present invention;

FIG. 3 is a schematic view of a braided three-strand woven hollow fiber membrane module;

FIG. 4 is a schematic view of a helically twisted hollow fiber membrane module;

fig. 5 is a schematic view of a conventional straight arrangement hollow fiber membrane module.

Detailed Description

The present invention will be described in further detail with reference to the following embodiments, which are illustrative only and not limiting, and the scope of the present invention is not limited thereby.

An internal pressure type hollow fiber membrane module device is shown in figure 1 and comprises a membrane module 18, a feed liquid tank 1, a pump 2,

pressure regulating valves

3 and 14 and a plurality of

switch valves

5, 6, 7 and 8, wherein the pump 2 and the feed pressure regulating valve 3 are arranged on a feed pipe which is connected with the feed liquid tank and the membrane module 18, the other end of the feed pipe is divided into two branches and is respectively connected with an upper port and a lower port of the membrane module 18, the upper feed switch valve 5 is arranged on a branch feed pipe which is connected with the upper port, and the lower feed switch valve 6 is arranged on a branch feed pipe which is connected with the lower port. The upper port of the membrane component 18 is connected with one end of an upper branch concentrated liquid pipe, the lower port of the membrane component 18 is connected with one end of a lower branch concentrated liquid pipe, a concentrated liquid switch valve 7 is installed on the upper branch concentrated liquid pipe, a lower concentrated liquid switch valve 8 is installed on the lower branch concentrated liquid pipe, the upper branch concentrated liquid pipe and the other end of the lower branch concentrated liquid pipe are connected with a concentrated liquid main pipe together, the concentrated liquid main pipe is connected with a feed liquid tank 1, and a filtered liquid outlet pressure regulating valve 14 and a pressure gauge 13 are installed on an outlet pipeline of filtered liquid of the membrane component 18.

The

valves

5, 6, 7, 8 are shown as on-off valves, which may be manual butterfly valves or ball valves, preferably automatic valves, such as pneumatic or electric ball valves, butterfly valves, etc.

The pressure of the feed liquid is increased from a feed liquid tank 1 through a delivery pump 2, the value of an inlet pressure gauge 4 of a membrane component 18 is adjusted to be 0.05-0.30MPa through a feed pressure adjusting valve 3, the feed liquid firstly passes through a fully-opened valve 6 and enters the membrane component 18 from a lower opening 9 of the membrane component 18, the concentrated feed liquid flows out of the membrane component 18 from an upper opening 10 and returns to the feed liquid tank 1 through a fully-opened valve 7, the filtered filtrate of the membrane flows out of the membrane device from an outlet 11 at the side of the membrane component 18 and is discharged out of the membrane device through an adjusting valve 14, and at the moment,

valves

5 and 8 are in a fully-closed state.

If the valve 14 and the pressure gauge 13 are not provided. The filtered filtrate flows out of the membrane device from the outlet 11 at the side of the membrane module 18, the outlet 11 at the side of the membrane module 18 is pressureless, and may have slightly low pressure due to the length, thickness and the like of the outlet pipeline of the membrane filtrate in the membrane device, and if tested, the reading of the pressure gauge 13 is 0-0.02 MPa. In the process of membrane filtration, because the

outlet valve

7 or 8 of the membrane concentrated solution is in a full-open state, and because of the length, the thickness and the like of a concentrated solution outlet pipeline, the pressure of the

outlet

9 or 10 of the concentrated solution of the membrane component 18 is 0-0.02 MPa. The invention adjusts the opening degree of the valve 14, so that the reading value of the pressure gauge 13 is 0.02-0.08MPa higher than the pressure value of the pressure gauge 17 at the concentrated solution outlet of the membrane module 18, and the optimal value is 0.03-0.05.

When the membrane separation device is filtered and operated for a certain time, along with the increase of membrane pollution, the flux of the filtered liquid of the membrane separation device is obviously reduced, the flowing direction of the feed liquid in the membrane tube pass is reversed, namely, the

valves

5 and 8 are fully opened, and the

valves

6 and 7 are fully closed. At this time, the feed liquid enters the membrane module 18 from the upper opening 10 of the membrane module 18 through the fully opened valve 5, the concentrated feed liquid flows out of the membrane module 18 from the lower opening 9, passes through the fully opened valve 8 and returns to the feed liquid tank 1, the filtered filtrate of the membrane still flows out of the outlet 11 on the membrane module 18 side, and is discharged out of the membrane filtration device through the regulating valve 14, and at this time, the

valves

6 and 7 are in a fully closed state. After the operation is maintained for a certain time, the flow direction of the feed liquid on the membrane tube pass is reversed again by switching the

valves

5, 6, 7 and 8 to be opened and closed again. Thus, the operation of membrane filtration of the feed liquid is completed by the periodical opening and closing switching of the

valves

5, 6, 7, 8. The reversal period of the flow direction of the feed liquid is determined according to the decline speed of the flux of the actual filtrate during the membrane filtration, and the reversal period of the invention is generally 10 to 60 minutes. The

valves

5, 6, 7, and 8 may be periodically opened and closed, automatically controlled by a program such as a PLC, or manually operated. The valve 12 is a low level evacuation valve of the membrane unit, which is closed during membrane filtration.

The invention adds a pressure gauge 13 and an adjusting valve 14 in the filtered fluid outlet pipeline of the membrane device, and the reading value of the filtered fluid pressure gauge 13 is 0.02-0.08MPa, preferably 0.03-0.05 by the adjusting valve 14 in the membrane filtration process. Thus, when feed liquid enters from the lower port 9 of the membrane module 18 and flows out from the upper port 10, the transmembrane pressure of the feed liquid entering the area of the inlet end is higher, so that the membrane filaments near the area of the inlet end are in a membrane filtration state with higher pressure. The transmembrane pressure of the membrane filaments far away from the inlet end (namely close to the outlet end) is gradually reduced due to the pressure loss caused by the flow resistance of the feed liquid in the membrane; when the pressure reading of the pressure gauge 13 at the side port 11 of the membrane component 18 is adjusted to be 0.02-0.08MPa by the valve 14, the pressure at the filtrate side in the membrane component 18 is greater than the pressure at the feed liquid concentration outlet of the membrane component 18, so that the transmembrane pressure of the membrane filaments close to the outlet end of the hollow fiber membrane is a negative value, and the membrane closest to the outlet end is not actually in a membrane filtration state, but is in a backwashing state, an isobaric flushing state and a micro-pressure state in sequence. I.e. the membrane closest to the inlet end zone is in a higher pressure membrane filtration state and the membrane closest to the outlet end zone is in a back-flush state. When the flow direction of the feed liquid is reversed, the inlet end and the outlet end of the hollow fiber membrane are exchanged, and the pressure at the filtered liquid side in the membrane component 18 is higher than the pressure at the concentrated outlet end of the feed liquid, so that the upper membrane filaments of the membrane component 18 which is just backwashed enter a membrane filtration state, and the lower membrane filaments with the most serious membrane pollution enter a backwashing state. By the periodical flow direction reversal of the feed liquid, the membrane filaments in the membrane filtration state in which the membrane filaments are in the high pressure are placed in the backwashing state, and the membrane filaments in the backwashing state are placed in the membrane filtration state in which the membrane filaments are in the high pressure. Namely, the inlet region with heavy membrane fouling is in the backwashing state with the best cleaning effect, and the region with less heavy membrane fouling is in the isobaric cleaning state.

According to the prior knowledge, the effect of backwashing on recovering the membrane flux is better than that of isobaric cleaning, so that the filtering efficiency of the membrane device can be improved. If the opening of the regulating valve 14 is too small, and the reading of the filtrate pressure gauge 13 is too large, the transmembrane pressure of the membrane filaments in the membrane filtration state is reduced, and meanwhile, backwashing can reduce the actual filtration capacity of the filtrate, so that the overall filtration efficiency of the membrane device is reduced, and therefore, the pressure value of the filtrate pressure gauge 13 is adjusted to be proper according to the actual pollution condition of the feed liquid. The preset pressure value can be adjusted manually or automatically in a pneumatic or electric mode.

The use method of the membrane component of the invention is that after the membrane component works for a certain time, the designed feed liquid flow direction reversing system is utilized to lead the feed liquid in the membrane component to reversely flow, so that the membrane filtration process and the membrane cleaning (backwashing and isobaric cleaning) process are simultaneously carried out, namely, one part of the membrane component is in the membrane filtration state, and the other part of the membrane component is in the backwashing and isobaric cleaning state. The more the certain end of the film in a working state is close to the end face of the film along with the lapse of working time, the more serious the pollution is, and the poorer the continuous working capability is; after the feed liquid inlets and the feed liquid outlets at the two ends of the membrane component are exchanged, namely, the inlet area with heavy membrane pollution is in a backwashing state with the best cleaning effect, and the area with less severe membrane pollution is in an isobaric cleaning state, so that the maximum functions of membrane separation and membrane cleaning can be ideally and fully exerted. The membrane filtering device overcomes the defects that the conventional membrane separation device needs to stop membrane filtering and off-line cleaning, and has the advantages of simple structure, convenient use, improved membrane filtering efficiency and the like.

Because the filtration side has a certain pressure, under the condition of maintaining the original transmembrane pressure of the membrane component, the inlet pressure value of the membrane component, namely the reading of a pressure gauge 4, can be increased, and the increased specific difference value can be close to or even exceed the value of the pressure gauge 13, so that the flow velocity of the feed liquid on the membrane filament tube pass can be increased, the shearing speed of the feed liquid on the membrane surface can be increased, and the membrane pollution is further reduced, meanwhile, because the feed liquid pressure inlet is increased, the internal pressure type hollow fiber membrane component with the length of 1 meter can be correspondingly increased to 1.2-2.0 meters, the floor area of the unit membrane area can be reduced, and the processing capacity of the unit floor area of the membrane device can be improved.

Referring to fig. 1, only 1 membrane module is schematically shown in all membrane filtration process diagrams of the present invention, and a plurality of membrane modules are arranged in parallel according to the requirement of actual membrane filtration throughput in a conventional manner to form a membrane device.

The valve switching system can adopt sequential cycle control of a time relay, PLC programming control and computer control. The pump 2 can be a common centrifugal water pump or a variable-frequency speed-regulating water pump, so that the pressure stability of a membrane separation system is ensured and the quality requirement of actual work is met.

The invention further designs another membrane filtration process and a membrane separation device thereof (see figure 2). A feed liquid concentrated solution outlet regulating valve 15, a switch valve 16 and a pressure gauge 17 are additionally arranged. The on-off valve 16 may be a manual butterfly valve or a ball valve, preferably an automatic valve, such as a pneumatic or electric ball valve, a butterfly valve, etc. The preset pressure value can be adjusted manually or automatically in a pneumatic or electric mode.

Through newly adding a feed concentrate outlet regulating valve 15, a switch valve 16 and a pressure gauge 17, the outlet side of the concentrated solution of the membrane component is also kept at a certain pressure in the membrane filtration process. Valve 16 is set to fully open for 1-5 minutes at the middle of each flow reversal cycle to create a pulse of feed solution to mitigate membrane flux drop due to membrane fouling. For example, when the reverse cycle is 14 minutes and the valve 16 is fully opened for 1 minute, it means that when the feed liquid is operated in the lower-in and upper-out mode to 7 minutes, the valve 16 is fully opened for 1 minute and then closed, and when the feed liquid is reversed in the upper-in and lower-out mode to 7 minutes, the valve 16 is fully opened for 1 minute and then closed.

And adjusting the opening degree of the reflux valve 15 to ensure that the reading of the pressure gauge 17 is 0.03-0.05MPa, and adjusting the opening degree of the valve 14 to ensure that the reading of the pressure gauge 13 is 0.01-0.05MPa higher than the reading of the pressure gauge 17, so as to ensure that one end of the membrane module is still in a backwashing state when the valve 16 is fully closed. When the valve 16 is fully opened, the pressure of the feed liquid concentration outlet is released, and the pulse cleaning effect is realized.

Example 1

The internal pressure type polyvinylidene fluoride hollow fiber membrane component (specification is

)，

10 membrane yarns are used as 1 strand, 3 strands of membrane yarns are braided into small membrane tows, and a plurality of membrane tows are arranged in a straight manner to form all the membrane yarns in the membrane component. The inner diameter of the polyvinylidene fluoride hollow fiber internal pressure film is 0.80 mm. 14 membrane modules are arranged in parallel to constitute a membrane apparatus. The membrane separation apparatus shown in FIG. 1 was used for concentration of an amino acid fermentation liquid. The wet weight of the fermentation liquid is 43g/L, and the fermentation liquid is treated by 5.3m 3. The pressure value of the inlet pressure gauge 4 is adjusted to 0.10 MPa, and the pressure of the pressure gauge 13 is adjusted to 0.030MPa by adjusting the valve 14. The flow direction reversal period of the feed liquid is set to be 20 minutes by the PLC, and concentration is carried out. After 42 minutes, the concentration multiple of the fermentation liquor reaches 12 times; the wet bacteria weight meets the concentration requirement.

Example 2

The internal pressure type polyvinylidene fluoride hollow fiber membrane module (specification is

) And spirally twisting the whole membrane wire, and filling the membrane wire into a membrane component shell to prepare the membrane forming component, wherein h is 10 cm. 14 membrane modules are arranged in parallel to constitute a membrane apparatus. The membrane separation apparatus shown in FIG. 1 was used for concentration of an amino acid fermentation liquid. The wet weight of the fermentation liquid is 43g/L, and the fermentation liquid is treated by 5.3m 3. The pressure value of the inlet pressure gauge 4 is adjusted to 0.10 MPa, and the pressure of the pressure gauge 13 is adjusted to 0.030MPa by adjusting the valve 14. The flow direction reversal period of the feed liquid is set to be 20 minutes by the PLC, and concentration is carried out. After 51 minutes, the concentration multiple of the fermentation liquor reaches 12 times; the wet bacteria weight meets the concentration requirement.

In the comparative example 1, the following examples were conducted,

an internal pressure type polyvinylidene fluoride hollow fiber membrane module (specification: standard) having a conventional structure as shown in FIG. 5 was used

) 14 membrane modules are arranged in parallel to constitute a membrane apparatus. The membrane separation apparatus shown in FIG. 1 was used for concentration of an amino acid fermentation liquid. The wet weight of the fermentation liquid is 43g/L, and the fermentation liquid is treated by 5.3m 3. The pressure value of the inlet pressure gauge 4 is adjusted to be 0.10 MPa, and the valve 14 is not arranged. The flow direction reversal period of the feed liquid is set to be 20 minutes by the PLC, and concentration is carried out. After 86 minutes, the concentration multiple of the fermentation liquor reaches 12 times; the wet bacteria weight meets the concentration requirement.

Example 3

) 14 membrane modules are arranged in parallel to constitute a membrane apparatus. The membrane separation apparatus shown in FIG. 1 was used for concentration of an amino acid fermentation liquid. The wet weight of the fermentation liquid is 43g/L, and the fermentation liquid is treated by 5.3m 3. The pressure value of the inlet pressure gauge 4 is adjusted to 0.3 MPa, and the pressure of the pressure gauge 13 is adjusted to 0.030MPa by adjusting the valve 14. The feed liquid flow direction reversal period was set to 14 minutes by the PLC for concentration. After 35 minutes, the concentration multiple of the fermentation liquor reaches 12 times; the wet bacteria weight meets the concentration requirement.

Example 4

By usingFIG. 3 shows an internal pressure type polyvinylidene fluoride hollow fiber membrane module (the diameter of the membrane module is still

) The length is 1 meter conventionally, can be increased to 1.5 meters, and 14 membrane modules are arranged in parallel to form a membrane device. The membrane separation apparatus shown in FIG. 1 was used for concentration of an amino acid fermentation liquid. The wet weight of the fermentation liquid is 43g/L, and the fermentation liquid is treated by 5.3m 3. The pressure value of the inlet pressure gauge 4 is adjusted to 0.25 MPa, and the pressure of the pressure gauge 13 is adjusted to 0.030MPa by adjusting the valve 14. The feed liquid flow direction reversal period was set to 14 minutes by the PLC for concentration. After 16 minutes, the concentration multiple of the fermentation liquor reaches 12 times; the wet bacteria weight meets the concentration requirement.

Example 5

) 14 membrane modules are arranged in parallel to constitute a membrane apparatus. The membrane separation apparatus shown in FIG. 2 was used for concentration of the amino acid fermentation liquid. The wet weight of the fermentation liquid is 43g/L, and the fermentation liquid is treated by 5.3m 3. The pressure value of the inlet pressure gauge 4 is adjusted to be 0.18 MPa, the pressure of the pressure gauge 17 is adjusted to be 0.030MPa by the adjusting valve 15, and the pressure of the pressure gauge 13 is adjusted to be 0.050MPa by the adjusting valve 14. The feed liquid flow direction reversal period was set by the PLC to 30 minutes, and the valve 16 was set to full open for 2 minutes at the 14 th minute from the start of each period, to perform concentration. After 31 minutes, the concentration multiple of the fermentation liquor reaches 12 times; the wet bacteria weight meets the concentration requirement.

Example 6

) 14 membrane modules are arranged in parallel to constitute a membrane apparatus. The membrane separation apparatus shown in FIG. 2 was used for concentration of the amino acid fermentation liquid. The wet weight of the fermentation liquid is 43g/L, and the fermentation liquid is treated by 5.3m 3. Adjusting the pressure value of the inlet pressure gauge 4 to 0.20 MPa, and adjusting the valve 15 to ensure thatThe pressure of the pressure gauge 17 is 0.030MPa, and the set value of the pressure gauge 13 is 0.05 MPa. The feed liquid flow direction reversal period was set by the PLC to 60 minutes, and the valve 16 was set to full open for 5 minutes at the 28 th minute from the start of each period, to perform concentration. After 33 minutes, the concentration multiple of the fermentation liquor reaches 12 times; the wet bacteria weight meets the concentration requirement.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various changes and modifications can be made without departing from the inventive concept, and these changes and modifications are all within the scope of the present invention.

Claims

1. A use method of an internal pressure type hollow fiber membrane component is characterized in that: and in the membrane filtration process, the pressure regulating valve is regulated to ensure that the pressure on the filtrate side is greater than the pressure at the concentrated solution outlet, so that the membrane close to the concentrated solution outlet is in a back flushing state, namely the membrane closest to the inlet end area is in a membrane filtration state with higher pressure, and the membrane closest to the outlet end area is in a back flushing state.

2. Use according to claim 1, characterized in that: the flow direction of the feed liquid in the membrane tube pass is periodically reversed.

3. Use according to claim 1, characterized in that: the side pressure of the filtrate of the membrane module is 0.02-0.08MPa higher than the outlet pressure of the concentrated solution of the membrane module.

4. Use according to claim 1 or 2 or 3, characterized in that: and a pipeline of the concentrated solution outlet is provided with a concentrated solution outlet pressure regulating valve and a switch valve.

5. Use according to claim 4, characterized in that: adjusting the pressure regulating valve on the concentrated solution outlet pipeline to make the pressure of the concentrated solution outlet side be 0.03-0.05 MPa.

6. Use according to claim 4, characterized in that: and opening the switch valve for 1-5 min in the middle period of each cycle of membrane filtration to realize pulse cleaning.

7. An apparatus for realizing the use method of the internal pressure type hollow fiber membrane module according to claim 1, characterized in that: comprises a membrane component, a feed liquid tank, a pump, a pressure regulating valve and a plurality of switch valves, wherein the feed liquid tank is connected with one end of a feed pipe, a pump and a feeding pressure regulating valve are arranged on the feeding pipe, the other end of the feeding pipe is communicated and connected with one end of two branch feeding pipes, the other end of the two branch feeding pipes is respectively connected with the upper port and the lower port of the membrane component, an upper feeding switch valve is arranged on the branch feeding pipe connected with the upper port, a lower feeding switch valve is arranged on the branch feeding pipe connected with the lower port, the upper port is connected with one end of the upper branch concentrated liquid pipe, the lower port is connected with one end of the lower branch concentrated liquid pipe, the upper branch concentrated liquid pipe is provided with a concentrated liquid switch valve, the lower branch concentrated liquid pipe is provided with a lower concentrated liquid switch valve, the other ends of the upper branch concentrated liquid pipe and the lower branch concentrated liquid pipe are connected with a concentrated liquid main pipe together, the concentrated liquid main pipe is connected with a stock solution tank, and an outlet pipeline of the filtered liquid is provided with a filtered liquid outlet pressure regulating valve and a pressure gauge.

8. The apparatus of claim 7, wherein: and a concentrated solution outlet pressure regulating valve and a pressure gauge are arranged on the concentrated solution main pipe.

9. The apparatus of claim 7 or 8, wherein: the membrane component inner membrane filaments adopt a braid-shaped three-strand weaving or spiral twisting form.