CN209221885U - An organic tubular membrane system for refined brine process - Google Patents

Abstract

The utility model relates to an organic tubular membrane system used in the process of refining brine, comprising at least one organic tubular membrane stack, the membrane stack inlet and the membrane stack outlet of the organic tubular membrane stack pass through a circulation pipe and a circulation pump connected to form a circulation system; the organic tubular membrane stack consists of at least two groups of organic tubular membrane components connected in series to form a whole. The utility model has the advantages of advanced technology, simple technological process, high quality of refined brine, high integration of organic tubular membrane system, small occupied area and strong anti-pollution ability. The organic tubular membrane system can filter out impurities such as suspended solids, colloids, and precipitates in crude salt, and has a high degree of integration and a small footprint. In addition, the filtration system composed of membrane tubes with special pore diameters and channels, coupled with the cross-flow filtration method prevents pollutants from accumulating on the membrane surface, which makes the organic tubular membrane have stronger anti-pollution ability, and the flux decay speed is slow. The chemical cleaning cycle is long.

Description

An organic tubular membrane system for refined brine process

technical field

The utility model belongs to the technical field of brine refining, and in particular relates to an organic tubular membrane system used in the process of refining brine.

Background technique

At present, the domestic chlor-alkali industry mainly adopts the ion-exchange membrane method to make alkali, and uses saturated brine as raw material to electrolyze to produce sodium hydroxide and other products. The OH ^- reaction generates insoluble matter and deposits on the ionic membrane, which seriously affects the life of the ionic membrane. Therefore, brine refining is extremely important in the production process of ionic membrane alkali production.

The domestic traditional primary brine refining process based on the "barrel reactor + Doyle clarifier + sand filter" process route has been basically eliminated. At present, domestic chlor-alkali enterprises mainly use the following two membrane filtration processes: Gore membrane, The organic microfiltration membrane technology represented by HVM membrane and the ceramic membrane cross-flow filtration technology.

The earlier membrane processes used in the purification of chlor-alkali industrial brine are two organic microfiltration membrane processes represented by Gore membrane and HVM membrane. The process route is that the crude brine first goes to the front reaction tank, and after adding sodium hydroxide and barium chloride, it enters the middle tank, and then pumps it into the pressurized air-dissolving tank, and enters the air flotation tank after decompression, and the clear liquid is discharged from the air flotation tank. The tank overflows, and sodium carbonate is metered into the post-reaction tank. After fully reacting, it is sent to a membrane filter to filter to obtain primary brine. The above-mentioned process adopts one-end filtration, the filter cake is easy to accumulate on the surface of the membrane, the flux drops rapidly, and the process membrane is seriously polluted; the process adopts the step-by-step separation method of calcium carbonate and magnesium hydroxide, and the pretreatment steps are complicated, resulting in a large one-time investment in equipment and occupying The land area is large; in addition, the membrane filter needs to be installed in a three-story factory building, which requires high civil engineering requirements and a large investment in civil engineering; the filter membranes used all have problems such as low composite strength of the filter membrane, and are easily corroded and damaged by salt water.

The ceramic membrane cross-flow filtration technology process is as follows: Add sodium hydroxide, sodium carbonate and barium chloride and other refined agents to the brine to react to form magnesium hydroxide, calcium carbonate and barium sulfate solid substances, and then add coagulation aids and oxidants for pretreatment , remove the magnesium hydroxide colloid and some solid particles through adsorption and co-precipitation, filter the brine with a ceramic membrane cross-flow filter, and the permeate through the ceramic membrane enters the ion exchange resin, and obtains refined brine after treatment. The impurity-rich brine that passes through the membrane is returned to pretreatment. This process adopts cross-flow filtration technology, which effectively reduces membrane fouling, but there are the following problems in practical application: (1) The ceramic membrane is brittle and easy to break, and needs to be shut down for repair if there is a problem, and a set of ceramic membrane modules is often required on site (2) The channel of the ceramic membrane is narrow, which is prone to blockage of the membrane channel; (3) The cleaning cycle of the ceramic membrane is short, and it needs to be cleaned once a week, and the concentration of the cleaning agent is high, which requires 15% hydrochloric acid soaking; High energy consumption and high investment costs.

Utility model content

The purpose of the utility model is to provide an organic tubular membrane system used in the process of refining brine, which can remove impurities such as suspended solids, colloids, and precipitates in brine, and obtain qualified refined brine.

The specific technical scheme is as follows:

An organic tubular membrane system for refining brine process, comprising at least one organic tubular membrane stack, the membrane stack inlet and the membrane stack outlet of the organic tubular membrane stack are connected to a circulation pump through a circulation pipe to form a circulation system ; The organic tubular membrane stack consists of at least two groups of organic tubular membrane modules connected in series to form a whole.

The optimal organic tubular membrane system is composed of 2-10 organic tubular membrane stacks connected in parallel.

In a further solution, adjacent organic tubular membrane modules are vertically and horizontally arranged, and one end of them is connected by a connecting pipe.

In a further solution, the organic tubular membrane system also includes a cleaning system, the cleaning system includes a cleaning pump and a cleaning liquid tank, and the output end of the cleaning pump passes through the backflush liquid pipe, the membrane stack circulation pipe and the organic tubular membrane respectively. The stack is connected; the backflush liquid pipe and the membrane stack circulation pipe are equipped with cleaning valves.

Control the opening and closing of the two cleaning valves between the backflushing liquid pipe and the cleaning pump and the organic tubular membrane stack, and add the backflushing liquid introduced by the cleaning pump from the backflushing port to each membrane tube in the organic tubular membrane module. Cleaning is carried out to remove the impurities attached to the surface of the membrane, thereby effectively reducing membrane pollution and restoring its membrane flux. The backflushing liquid uses filtrate, and finally flows out from the outlet of the concentrated liquid to realize recycling. The cleaning agent (0.5% hydrochloric acid concentration) can also be introduced from the inlet of the membrane stack through the cleaning pump to clean the surface impurities of the membrane tubes in each organic tubular membrane module.

In a further solution, the organic tubular membrane module includes several membrane tubes arranged horizontally inside the housing, and the two ends of the membrane tubes are snapped with installation covers that are sealed and connected to the housing, so that the outer wall of the membrane tubes A sealed cavity is formed between the installation cover and the openings at both ends of the membrane tube respectively communicated with the outside world, and a filtrate outlet communicated with the sealed cavity is provided on the casing.

The membrane tube of the utility model refers to a membrane tube of an organic tubular membrane, and its structure is existing.

In a further solution, the housing is provided with a backflush port communicating with the sealed cavity, and the filtrate outlet and the backflush port are located on the diagonal of the organic tubular membrane module; the backflush port is connected to the The output end of the backwash liquid pipe is connected, and the output end of the membrane stack circulation pipe is connected with the membrane stack inlet or membrane stack outlet.

Preferably, the organic tubular membrane stack is composed of 3-8 groups of organic tubular membrane modules in series, wherein all filtrate outlets are connected with filtrate pipes to lead to the organic tubular membrane system, and all backflush ports All are connected to the output end of the cleaning pump through the backflushing liquid pipe.

In a further solution, the outer diameter of the housing is 6-10 inches and the length is 3m-4m; the membrane tube is a tubular structure with an internal channel diameter of 5mm-8mm; the membrane material of the membrane tube is polyvinylidene fluoride Ethylene, polyethersulfone, polysulfone or polyacrylonitrile, the membrane pore diameter of the membrane tube is 10-50nm.

In a further solution, a booster pump and a concentrate pipe are respectively connected to the circulation pipe, and a first switching valve, a second switching valve, a third switching valve and a fourth switching valve are respectively installed on the circulation pipes at both ends of the circulating pump; The circulating pump, the first switching valve, the organic tubular membrane stack, and the second switching valve form a reverse cycle, and the circulating pump, the third switching valve, the organic tubular membrane stack, and the fourth switching valve form a forward cycle. cycle.

In order to give full play to the filtration efficiency of the organic tubular membrane system, 4 switching valves are added to the system to realize the automatic reversing function of the material in and out of the organic tubular membrane stack in the organic tubular membrane system. When the first switching valve, When the second switching valve is opened, and the third switching valve and the fourth switching valve are closed, the original liquid flows in from the membrane modules located at the lower part of the organic tubular membrane stack, and flows upwards through each organic tubular membrane module in turn, and the retained concentrated The liquid flows out from the membrane module located at the upper part of the organic tubular membrane stack, and the filtered filtrate enters the filtrate pipe from the filtrate outlet of each organic tubular membrane module for recovery. After the set time is reached, when the first switching valve and the second switching valve are automatically closed, the third switching valve and the fourth switching valve are automatically opened. At this time, the brine flows in from the membrane module located on the upper part of the organic tubular membrane stack, and flows downward in sequence. After flowing through each organic tubular membrane module, the intercepted concentrated liquid flows out from the membrane module located at the lower part of the organic tubular membrane stack, and so on. After filtration, the filtrate and the concentrate were collected separately. That is, through the automatic reversing function of the material in and out of the organic tubular membrane stack, the surface of the membrane tubes in each organic tubular membrane module can be reversed and washed, so that the impurities attached to the surface of the membrane tubes can be removed, effectively reducing the At the same time, it also solves the problem of high pressure and heavy load of the front-stage organic tubular membrane module in the organic tubular membrane stack, while the problem of low pressure and light load of the latter-stage organic tubular membrane module prolongs the entire organic membrane stack. The service life of the tubular membrane stack.

The organic tubular membrane system of the utility model is applied to the refining of brine, wherein the raw liquid inlet of the organic tubular membrane system is connected to the outlet of the reaction tank of refined brine, and the filtrate outlet of the organic tubular membrane system is connected to the refined brine tank. The concentrated liquid outlet of the organic tubular membrane system is connected to a filter press, and the filtrate outlet of the filter press is connected to a reaction tank; the feed end of the reaction tank is connected to a crude brine tank through a baffle tank.

The channel diameter of the membrane tube in the organic tubular membrane of the device is 5mm-8mm, so that it has a wider membrane channel. When in use, the membrane channel will not be blocked and the filtration quality is guaranteed.

The membrane tube in this device is a tubular structure formed by winding a membrane material with a membrane aperture of 10-50nm. The membrane tube has a narrow pore size distribution and high filtration accuracy, making it difficult for suspended solids, colloids, and large particles of impurities to enter the membrane pores. It belongs to ultrafiltration in the true sense, so the quality of filtered brine is higher and more stable.

The utility model adopts a filtration system composed of membrane tubes with special pore diameters and channels, and the cross-flow filtration mode prevents pollutants from accumulating on the membrane surface, so that the organic tubular membrane has a stronger anti-pollution ability and a slower flux decay rate . Therefore, the chemical cleaning cycle of the organic tubular membrane of the present utility model is long, and the chemical cleaning cycle is greater than 1 month; in addition, because the pollutants are not easy to accumulate in the membrane pores, and the thickness of the membrane layer is only 20 μm, the pollution in the membrane tube The amount of substances is small, so the membrane performance can be restored by using a low concentration of hydrochloric acid cleaning agent (concentration 0.5%).

The organic tubular membrane system of the utility model can be used to filter impurities such as suspended solids, colloids, and precipitates in crude salt. In addition, the filtration system has a high degree of integration and a small footprint.

The organic tubular membrane is composed of several membrane tubes, and the number of membrane tubes is set according to the inner diameter of the shell and actual needs. The two ends of the membrane tube are sealed together to form a cavity inside the shell; in addition, the membrane tube has a certain degree of flexibility, and there will be no leakage or breakage of the membrane tube, which can ensure continuous and stable production.

Description of drawings

Fig. 1 is a schematic diagram of the utility model principle,

Fig. 2 is the structural representation of the organic tubular membrane module in the utility model,

Figure 3 is a schematic cross-sectional view of Figure 2,

Fig. 4 is the structural representation of the organic tubular membrane stack in the utility model,

Fig. 5 is a structural schematic diagram of an organic tubular membrane refining brine device in the present invention.

In the figure: 10-Organic tubular membrane module, 11-Shell, 12-Membrane tube, 13-Backflush port, 14-Filtrate outlet; 20-Organic tubular membrane stack, 21-Membrane stack outlet, 22-Membrane Stack inlet, 23-connecting pipe; 31-booster pump, 32-circulation pump, 33-cleaning pump; 40-circulation pipe, 50-concentrated liquid pipe, 60-filter liquid pipe, 71-first reversing valve, 72 -Second reversing valve, 73-third reversing valve, 74-fourth reversing valve, 75-valve; 80-cleaning liquid tank; 90-organic tubular membrane system, 101-coarse brine tank, 102-fold Launder, 103-reaction barrel, 104-filter press, 105-refined brine bucket.

Detailed ways

In order to further understand the utility model, the preferred embodiment of the utility model is described below in conjunction with the examples, but it should be understood that these descriptions are only for further illustrating the features and advantages of the utility model, rather than limiting the utility model claims.

Below in conjunction with accompanying drawing 1-5, the utility model is described in detail:

Example 1:

As shown in Figure 1, a kind of organic tubular membrane system that is used for refining brine process comprises at least one organic tubular membrane stack 20, between the membrane stack inlet 21 of the organic tubular type membrane stack 20 and the membrane stack outlet 22 The circulation system is formed by connecting the circulation pipe 40 with the circulation pump 32; the organic tubular membrane stack 20 is formed as a whole by at least two groups of organic tubular membrane modules 10 connected in series.

The optimal organic tubular membrane system is composed of 2-10 organic tubular membrane stacks connected in parallel.

In a further solution, adjacent organic tubular membrane modules 10 are vertically and horizontally arranged, and one end of them is connected by a connecting pipe 23 .

In a further solution, the organic tubular membrane system also includes a cleaning system, the cleaning system includes a cleaning pump 33 and a cleaning liquid tank 80, and the output end of the cleaning pump 33 passes through the backflush liquid pipe, the membrane stack circulation pipe and the organic The tubular membrane stack 20 is connected; the backflush liquid pipe and the membrane stack circulation pipe are both provided with a cleaning valve 75 .

Control the opening and closing of the two backflush valves between the backflush liquid pipe and the cleaning pump and the organic tubular membrane stack, add the backflush liquid introduced by the cleaning pump from the backflush port to The tube is cleaned to remove the impurities attached to the membrane surface, thereby effectively reducing membrane fouling and restoring its membrane flux. The backflushing fluid is the filtrate, which finally flows out from the outlet of the concentrated solution to realize recycling. The cleaning agent (0.5% hydrochloric acid concentration) can also be introduced from the inlet of the membrane stack through the cleaning pump to clean the surface impurities of the membrane tubes in each organic tubular membrane module.

As a further solution, as shown in Figures 2 and 3, the organic tubular membrane module 10 includes several membrane tubes 12 arranged horizontally inside the housing 11, and the two ends of the membrane tubes 12 are clamped with the housing. 11 is a mounting cover for sealing connection, so that a sealed cavity is formed between the outer wall of the membrane tube 12 and the mounting cover; the openings at both ends of the membrane tube 12 communicate with the outside world respectively, and the housing 11 is provided with a sealing cavity Body connected filtrate outlet 14.

In a further solution, the housing 11 is provided with a backflush port 13 communicating with the sealed cavity, and the filtrate outlet 14 and the backflush port 13 are located on the diagonal of the organic tubular membrane module 10; the backflush The port 13 is connected to the output end of the backflush liquid pipe, and the output end of the membrane stack circulation pipe is connected to the membrane stack inlet 21 or the membrane stack outlet 22 .

Preferably, the organic tubular membrane stack 20 is formed by connecting 3-8 groups of organic tubular membrane modules 10 in series, wherein all the filtrate outlets 14 are connected with the filtrate pipe 60 to lead to the organic tubular membrane system, all The backflushing ports 13 are all connected to the output end of the cleaning pump 33 through the backflushing liquid pipe.

In a further solution, the outer diameter of the housing 11 is 6-10 inches, and the length is 3m-4m; the membrane tube 12 is a tubular structure, and the diameter R of its internal channel is 5mm-8mm; the membrane material of the membrane tube is Polyvinylidene fluoride, polyethersulfone, polysulfone or polyacrylonitrile, the membrane pore diameter of the membrane tube is 10-50nm.

In a further solution, a booster pump 31 and a concentrate pipe 50 are respectively connected to the circulation pipe 40, and a first switch valve 71, a second switch valve 72, and a third switch valve are respectively installed on the circulation pipe 40 at both ends of the circulation pump 32. Valve 73 and the fourth switching valve 74; the circulating pump 32, the first switching valve 71, the organic tubular membrane stack 20, and the second switching valve 72 form a reverse cycle, and the circulating pump 32, the third switching valve 73 , the organic tubular membrane stack 20, and the fourth switching valve 74 form a forward cycle.

When the organic tubular membrane system is in use, the coarse brine to be filtered is introduced into the circulation pipe 40 through the booster pump 31. When the first switching valve 71 and the second switching valve 72 are opened, the third switching valve 73 and the fourth switching valve are opened. When the switching valve 74 is closed, the raw liquid flows in from the membrane modules located at the lower part of the organic tubular membrane stack 20, and flows upwards through each organic tubular membrane module 10 in turn, and then the intercepted concentrated solution flows from the upper part of the organic tubular membrane stack 20. The membrane module flows out, and the filtered filtrate enters the filtrate pipe 60 from the filtrate outlet 14 of each organic tubular membrane module 10 for recovery. After the set time is reached, when the first switching valve 71 and the second switching valve 72 are automatically closed, the third switching valve 73 and the fourth switching valve 74 are automatically opened. The module flows in and flows down through each organic tubular membrane module 10 sequentially, and the intercepted concentrated liquid flows out from the membrane module located at the lower part of the organic tubular membrane stack 20, and so on. It not only achieves filtration, but also achieves the effect of reversing and scouring the surface of each membrane tube in the organic tubular membrane module 10, thereby preventing impurities from adhering to the surface of the membrane tubes, effectively reducing the pollution of the membrane tubes; In the membrane module, the front-stage organic tubular membrane has high pressure and heavy load, while the rear-stage organic tubular membrane has low pressure and light load, and the service life of the membrane module is extended as a whole.

When impurities are attached to the surface of the membrane tube 12, a certain pressure of filtrate is added from the backflush liquid pipe, and enters from the backflush port 13 on each organic tubular membrane module 10, and the surface of each membrane tube 12 is cleaned, and then It flows out from the outlet of the concentrated solution, and is exported to the organic tubular membrane system through the concentrated solution pipe 50, and at the same time, the impurities attached to the surface of the membrane tube are washed off, thereby effectively reducing membrane fouling and restoring its membrane flux. Backwashing is generally every 8-10 hours.

When used for a period of time such as more than 1 month, low-concentration hydrochloric acid cleaning agent (concentration 0.5%) can be directly added from the membrane stack inlet of the organic tubular membrane stack 20 into the membrane tubes in each organic tubular membrane module 10 In step 12, cleaning the surface of each membrane tube can restore the membrane performance to its original state.

Example 2:

The organic tubular membrane system of the present utility model is applied to brine refining. As shown in FIG. The filtrate outlet is connected to the refined brine barrel 105, and the concentrate outlet of the organic tubular membrane system 90 is connected to the filter press 104, and the filter press outlet of the filter press 104 is connected to the reaction barrel 103; The feed end is connected with the crude brine tank 101 through the baffle tank 102 .

Example 3:

The process of refining brine is as follows (as shown in Figure 1):

S1: The coarse brine to be treated is first sent into the baffle tank, and the refined preparations NaOH and Na ₂ CO ₃ are metered into the baffle tank, and then flow into the reaction tank, wherein the Mg ²⁺ and Ca ²⁺ in the crude brine are mixed with NaOH respectively , Na ₂ CO ₃ react to generate Mg(OH) ₂ , CaCO ₃ solid substances; the amount of NaOH added is 0.1-0.3 g/L after reacting with Mg ²⁺ , and the amount of Na ₂ CO ₃ added is after reacting with Ca ²⁺ Excessive 0.3 ~ 0.5g/L.

S2: The crude brine after the refining reaction is sent to the filtration system, and the organic tubular membrane stack intercepts impurities such as suspended solids, colloids, and sediments in the crude brine, and the brine that passes through the organic tubular membrane stack is the refined brine;

S3: The concentrated liquid intercepted by the organic tubular membrane stack is sent to the filter press, the pressed salt mud is transported outside for treatment, and the filtered liquid is returned to the reaction tank for recycling treatment.

The filtration system of the utility model is used to directly filter the brine after the refined reaction, and remove impurities such as Mg(OH ₎ colloid, _CaCO precipitation and suspended matter in the brine, and pass through the organic tubular membrane stack. The total content of Ca ²⁺ and Mg ²⁺ in refined brine is <1mg/L, SS<1mg/L, and turbidity<0.5NTU.

The filtration method of the organic tubular membrane stack in the utility model is internal pressure filtration, its operating pressure is 0.1~0.6MPa, and the membrane surface flow rate is 1m/s-3m/s.

That is, the specific examples of refined brine are as follows:

One: The crude brine in the crude brine bucket is chemical brine, with a Ca ²⁺ content of 0.61g/L and a Mg ²⁺ content of 0.05g/L. It is directly pumped into the baffle tank, and sodium carbonate 1.95g/ L and sodium hydroxide 0.30g/L, and then flow into the reaction tank, wherein, Mg ²⁺ and Ca ²⁺ in the chemical salt react with NaOH and Na ₂ CO ₃ to generate Mg(OH) ₂ and CaCO ₃ solid substances, which are refined The crude brine after the reaction is sent to the organic tubular membrane system, which is composed of 5 organic tubular membrane stacks connected in series, and each organic tubular membrane stack is connected in series with 6 organic tubular membrane stacks with a diameter of 10 inches and a length of 4m. Membrane module, the channel of the membrane tube in the organic tubular membrane module is 5mm, the pore size is 30nm, the membrane material is polyvinylidene fluoride, and the working method of the filtration system is as described above. The operating pressure is controlled to 0.35MPa, and the membrane surface flow rate is 1.5m/s. Impurities such as Mg(OH) ₂ colloids, CaCO ₃ precipitates and suspended solids in brine generated by the reaction are intercepted, and the refined salt that passes through the organic tubular membrane stack The total content of Ca ²⁺ and Mg ²⁺ in the water is 0.65mg/L, SS=0.36mg/L, and turbidity is 0.20NTU. The salt mud is transported outside for treatment, and the filtrate is returned to the reaction tank for recycling.

Two: The crude brine in the crude brine bucket is the brine extracted from the mine, the content of Ca ²⁺ is 1.38g/L, and the content of Mg ^{2+ is} 0.22g/L. It is directly pumped into the baffle tank and metered into the baffle tank Sodium carbonate 4.1g/L and sodium hydroxide 0.20g/L, then flow into the reaction barrel, wherein, Mg ²⁺ and Ca ²⁺ in the brine react with NaOH and Na ₂ CO ₃ respectively to form Mg(OH) ₂ and CaCO ₃ The solid matter and crude brine after refined reaction are sent to the filtration system. The organic tubular membrane system is composed of an organic tubular membrane stack. The organic tubular membrane stack is connected in series with 4 organic tubular membrane modules with a diameter of 6 inches and a length of 3m. , the channel of the membrane tube is 8mm, the pore size is 30nm, the membrane material is polyvinylidene fluoride, and the working method of the filtration system is as above. The operating pressure is controlled to 0.45MPa, and the membrane surface flow rate is 2.5m/s. Impurities such as Mg(OH) ₂ colloids, CaCO ₃ precipitates and suspended solids in the brine generated by the reaction are intercepted, and the refined salt that passes through the organic tubular membrane stack The total content of Ca ²⁺ and Mg ²⁺ in the water is 0.82mg/L, SS=0.47mg/L, and turbidity is 0.33NTU. The salt mud is transported outside for treatment, and the filtrate is returned to the reaction tank for recycling.

It should be noted that the above embodiments are only used to illustrate the technical solutions of the present utility model, and are not intended to limit it; although the utility model has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: it still The technical solutions described in the foregoing embodiments may be modified, or some of the technical features may be equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and spirit of the technical solutions of the various embodiments of the present invention. scope.

Claims (8)

1. a kind of organic tubular type membranous system for refined brine technique, it is characterised in that: including at least one organic tubular membrane Heap (20) passes through circulation pipe (40) and follows between the membrane stack import (21) of organic tubular type membrane stack (20) and membrane stack outlet (22) Ring pump (32) connection forms the circulatory system；Organic tubular type membrane stack (20) is connected by the organic tubular membrane component of at least two groups (10) Form an entirety.

2. a kind of organic tubular type membranous system for refined brine technique according to claim 1, it is characterised in that: adjacent Organic tubular membrane component (10) arranges that one end is connected by connecting tube (23) in vertical equity.

3. a kind of organic tubular type membranous system for refined brine technique according to claim 1, it is characterised in that: described Organic tubular type membranous system further includes cleaning system, and the cleaning system includes cleaning pump (33), the output of the cleaning pump (33) End is connect by recoil liquid pipe, membrane stack circulation pipe with organic tubular type membrane stack (20) respectively；The recoil liquid pipe and membrane stack circulation pipe On be equipped with wash-out valve (75).

4. a kind of organic tubular type membranous system for refined brine technique according to claim 1-3, feature Be: organic tubular membrane component (10) includes several horizontal layouts membrane tube (12) internal in shell (11), the film The both ends of pipe (12) are installed with the installation lid being connected and sealed with shell (11), make the outer wall of membrane tube (12) and install lid Between formed a seal cavity；The both ends open of the membrane tube (12) is in communication with the outside respectively, offers on the shell (11) The filtrate outlet (14) being connected to seal cavity.

5. a kind of organic tubular type membranous system for refined brine technique according to claim 4, it is characterised in that: described The recoil mouth (13) being connected to seal cavity is offered on shell (11), the filtrate outlet (14) and recoil mouth (13) are located at On the diagonal line of organic tubular membrane component (10)；Recoil mouth (13) connect with the output end for the liquid pipe that recoils, and the membrane stack follows The output end of endless tube is connect with membrane stack import (21) or membrane stack outlet (22).

6. a kind of organic tubular type membranous system for refined brine technique according to claim 5, it is characterised in that: described Organic tubular type membrane stack (20) is connected in series by the organic tubular membrane component of 3-8 group (10), wherein all filtrate outlets (14) It is connect with filtering liquid pipe (60) and exports organic tubular type membranous system, all recoil mouths (13) pass through the recoil liquid pipe It is connect with the output end of cleaning pump (33).

7. a kind of organic tubular type membranous system for refined brine technique according to claim 5, it is characterised in that: described The outer diameter of shell (11) is 6-10 inches, length 3m-4m；The membrane tube (12) is tubular structure, and inner passage diameter is 5mm-8mm；The membrane material of the membrane tube is Kynoar, polyether sulfone, polysulfones or polyacrylonitrile, and the membrane aperture of the membrane tube is 10-50nm。

8. a kind of organic tubular type membranous system for refined brine technique according to claim 1, it is characterised in that: described It is connected separately with booster pump (31) and concentration liquid pipe (50) on circulation pipe (40), is located at the circulation pipe (40) at circulating pump (32) both ends On be separately installed with the first switching valve (71), the second switching valve (72), third switching valve (73) and the 4th switching valve (74)；It is described Circulating pump (32), the first switching valve (71), organic tubular type membrane stack (20), the second switching valve (72) form a recycled back, institute It states circulating pump (32), third switching valve (73), organic tubular type membrane stack (20), the 4th switching valve (74) and forms a forward circulation.