CN210752133U

CN210752133U - Device for producing polyolefin substrate composite reverse osmosis membrane

Info

Publication number: CN210752133U
Application number: CN201920863851.7U
Authority: CN
Inventors: 程跃; 陆宝春; 邱长泉; 王英杰
Original assignee: Shanghai Energy New Materials Technology Co Ltd
Current assignee: Shanghai Energy New Materials Technology Co Ltd
Priority date: 2019-06-11
Filing date: 2019-06-11
Publication date: 2020-06-16
Anticipated expiration: 2029-06-11

Abstract

The utility model relates to a device for producing a polyolefin substrate composite reverse osmosis membrane, which comprises an unreeling device, a pretreatment tank, a cleaning tank, an amine solution tank, an air knife and a TMC solution tank from the trend of the membrane; the horizontal distance of the unreeling device from the pretreatment tank is 1.5 meters, the horizontal distance of the pretreatment tank from the cleaning tank is 0.5 meters, the horizontal distance of the cleaning tank from the amine solution tank is 0.5 meters, the vertical distance of the amine solution tank from the air knife is 0.5 meters, and the horizontal distance of the TMC solution tank from the amine solution tank is 0.5 meters. This application needs unreel to add pretreatment tank and washing tank between the amine solution groove, and more a base film pretreatment process than traditional polysulfone base film, makes the polyolefin base film possess the effect of adsorbing sufficient amine, possesses the ability of carrying out continuous large-scale industrial production with the polyolefin base after the equipment improves.

Description

Device for producing polyolefin substrate composite reverse osmosis membrane

Technical Field

The utility model relates to a filter membrane technical field, specific device of compound reverse osmosis membrane of production polyolefin basement that says so.

Background

The membrane water treatment technology is a method for separating, enriching and purifying each component in a solvent by utilizing a membrane with selective permeation, has the advantages of high efficiency, energy conservation, simple process and the like, and is a core process of the current water treatment technology. Membranes are classified into microfiltration membranes, ultrafiltration membranes, nanofiltration membranes and reverse osmosis membranes according to the pore size. The aperture of the nanofiltration membrane is between the ultrafiltration membrane and the reverse osmosis membrane and is about 1nm, and the molecular weight cutoff is 300-500 daltons. Generally, the nanofiltration membrane is considered to have a synergistic effect of sieving and southwest effect, so that relatively high permeability can be ensured and high salt-cutting performance is achieved, and the nanofiltration membrane is widely concerned and researched by domestic and foreign scholars and is developed rapidly in recent years.

At present, a common composite nanofiltration membrane is mainly prepared by an interfacial polymerization method and consists of a loose porous basement membrane and a thin and compact skin layer. The base film serves as a support layer to provide mechanical strength to the membrane as a whole, while the skin layer serves to provide selective separation capability to the membrane. The performance of the substrate material is very important for the nanofiltration membrane, the strength and stability of the substrate determine the service environment and the service life of the membrane, and the large aperture and the high porosity of the substrate provide preconditions for the high flux of the membrane. The traditional substrate materials such as cellulose acetate, polyacrylonitrile, polyarylsulfone, polyethersulfone and the like are used, and the prepared substrate has the advantages of ultra-filtration size, low self flux, poor acid and alkali resistance, poor oxidation resistance and poor solvent resistance and greatly limited use conditions.

Polyolefin materials such as polyethylene, polypropylene and other thermoplastic resins have excellent mechanical strength and physical and chemical properties, and have various advantages in preparing microporous film materials, such as thin film thickness and low medium permeation resistance; the membrane aperture is larger, and the modifiable space is larger; strong acid and alkali resistance, strong oxidation resistance and corrosion resistance, good long-term stability and the like. But the polyolefin material has low surface energy and high hydrophobicity, so that the surface wettability is poor, and liquid is difficult to naturally permeate; the hydrophobicity also causes a large amount of accumulation of the intercepted matters on the surface of the membrane in the filtration process, the membrane pollution is serious, the water flux is reduced, and the separation capacity is reduced. And thus is particularly important for the modification of hydrophobic polyolefin materials. In the prior art, a codeposition method is adopted, and an organic solvent and a hydrophilic agent are used for modifying a polyolefin substrate film, so that the dyne value of a hydrophobic interface is improved, and thus, the interfacial polymerization reaction can be carried out on the substrate.

At present, production lines at home and abroad are suitable for supporting a polysulfone ultrafiltration membrane by non-woven fabrics, the polysulfone ultrafiltration membrane is directly immersed into an amine solution tank after being unreeled, and due to the hydrophobicity of a polyolefin substrate, the amine solution cannot be immersed into the amine solution, and the amine solution has insufficient adsorption capacity, so that a complete semipermeable membrane cannot be formed during interfacial polymerization.

SUMMERY OF THE UTILITY MODEL

In order to solve the problems in the prior art, the device is suitable for novel production of the polyolefin-based composite reverse osmosis membrane.

The method is realized through the following technical scheme.

A device for producing a polyolefin substrate composite reverse osmosis membrane comprises an unreeling device, a pretreatment tank, a cleaning tank, an amine solution tank, an air knife and a TMC solution tank from the direction of the membrane;

the horizontal distance of the unreeling device from the pretreatment tank is 1.5 meters, the horizontal distance of the pretreatment tank from the cleaning tank is 0.5 meters, the horizontal distance of the cleaning tank from the amine solution tank is 0.5 meters, the vertical distance of the amine solution tank from the air knife is 0.5 meters, and the horizontal distance of the TMC solution tank from the amine solution tank is 0.5 meters.

The cloth feeding distance from the unreeling process position to the pretreatment process position is 3 meters, the cloth feeding distance from the pretreatment tank process position to the inner side of the pretreatment tank is 4 meters, the cloth feeding distance from the pretreatment process position to the cleaning process position is 2 meters, the cloth feeding distance from the cleaning tank process position to the amine solution tank is 6 meters, the cloth feeding distance from the cleaning tank process position to the amine solution tank is 2 meters, the cloth feeding distance from the amine solution process position to the air knife process position is 1 meter, the cloth feeding distance from the amine solution tank process position to the air knife process position is 0.5 meter, the cloth feeding distance from the air knife process position to the TMC solution tank process position is 2 meters, and the cloth feeding distance from the TMC solution tank process position to the inner side;

the pretreatment tank is used for polyolefin substrate pretreatment, and can be a water tank, a slit extrusion mode, a spraying mode and the like.

The cleaning tank is used for cleaning the polyolefin substrate in the pretreatment from redundant solvent.

A method for continuously preparing a polyolefin substrate composite reverse osmosis membrane comprises the following steps;

and carrying out plasma treatment or corona treatment on the polyolefin microporous base membrane, and rolling for later use.

The polyolefin microporous base membrane is made of one of polyethylene, polypropylene, polytetrafluoroethylene and polyvinylidene fluoride; polyethylene is preferred.

The porosity of the polyolefin microporous base membrane is 30-50%, the average pore diameter is 0.02-0.4 micrometer, and the average thickness is 5-60 micrometers;

the pretreatment comprises one or more of polyvinyl alcohol, surfactant and organic solvent which are combined according to different proportions.

The alcoholysis degree of the polyvinyl alcohol PVA is 80.0-99.8 mol%, and the molecular weight is 80000-180000.

The surfactant is one of sodium dodecyl benzene sulfonate, sodium dodecyl sulfate, sodium polystyrene sulfonate, glycerin, polyethylene glycol and polyoxyethylene nonylphenol ether.

The organic solvent is DMF, DMAc, NMP, DMSO, ethanol, isopropanol, etc

And (2) soaking the polyolefin microporous base membrane into a pretreatment tank, soaking the polyolefin microporous base membrane into a water tank after the polyolefin microporous base membrane is completely soaked, then soaking the polyolefin microporous base membrane into an amine solution tank, air-drying the surface of the membrane by using an air knife, and then soaking the membrane into a TMC solution tank for interfacial polymerization. Then entering a curing area, wherein the temperature is 60-80 ℃, and the curing time is 100-.

The polyamine is selected from one of piperazine, m-phenylenediamine, p-phenylenediamine, o-phenylenediamine and benzenetriamine;

the mass fraction of the polyamine in the aqueous phase solution is 1-3%, the mass fraction of the acid acceptor in the aqueous phase solution is 0.5-2%, and the mass fraction of the additive in the aqueous phase solution is 0.01-0.05%;

the acid acceptor is sodium hydroxide.

Preparing a polyacyl chloride oil phase solution: dissolving poly acyl chloride in an organic solution, wherein the poly acyl chloride oil phase solution is selected from one of trimesoyl chloride, paraphthaloyl chloride, isophthaloyl chloride and phthaloyl chloride;

the mass fraction of the polyacyl chloride in the polyacyl chloride solution is 0.1-0.5%.

The organic solvent is n-hexane, ISOPAR E, ISOPAR G, ISOPAR H, ISOPAR L, ISOPAR C, cyclohexane, pentane, heptane, octane, etc.

Pure water flux: and (3) measuring by using a reverse osmosis filter membrane tester (self-made).

Retention rate: the measurement was carried out by using a conductivity meter (DDS-307A, Rehmagnet, Shanghai).

Flux and rejection: pure water flux is an important parameter for representing the water permeability of the separation membrane, and the membrane is pre-pressed for 1h by using 2000mg/L NaCl solution to be tested as feed liquid under the pressure of 1.5MPa to ensure that the effluent is stable;

the calculation formula is as follows:

wherein Q is the volume (L) of pure water passing therethrough, Δ t is the time (h) of passing therethrough, and A is the effective area (cm) of the permeable membrane²)。

Retention performance: the retention rate (R) is two indexes. After the membrane pre-pressing is finished, the pressure is adjusted to 1.5MPa by using 2000mg/L NaCl solution to be tested, and the material temperature is tested at 25 ℃. The calculation formula is as follows:

C_Pand C_FThe permeate and feed concentrations (mg/L), respectively, are generally considered to be linearly related to the salt concentration, and thus the salt cut-off R can be calculated using conductivity instead of concentration.

The experimental results are shown in table one:

TABLE 1

	J(GFD)	R(％)
			Experimental group	25-30	98.5-99.4
Control group	157-262	0

The experimental group is the performance data of the production line production film with the pretreatment and cleaning device, and the comparison group is the performance data of the production film of the pilot scale production line of the cleaning tank device without the pretreatment. The polyethylene-based film without pretreatment cannot form a complete desalting layer on the surface of the film.

Drawings

FIG. 1 is a schematic view of the utility model;

the direction of the arrow in the figure is the film running direction.

The labels in the figures are:

1, unwinding equipment is adopted, wherein the unwinding equipment comprises unwinding equipment,

2, a pretreatment tank is arranged in the device,

3 a cleaning tank is arranged on the upper portion of the tank,

4 an amine solution tank, wherein the amine solution tank is provided with a plurality of amine solution tanks,

5, an air knife is arranged at the air inlet of the air knife,

6 TMC solution tank.

Detailed Description

The technical solution of the present invention is further defined in the following with reference to the accompanying drawings and the detailed description.

Example (b):

as shown in fig. 1, the device for producing the polyolefin substrate composite reverse osmosis membrane comprises an unreeling device 1, a pretreatment tank 2, a cleaning tank 3, an amine solution tank 4, an air knife 5 and a TMC solution tank 6 from the direction of the membrane;

The cloth feeding distance from the unreeling process position to the pretreatment process position is 3 meters, the cloth feeding distance from the pretreatment tank process position to the pretreatment tank process position is 4 meters, the cloth feeding distance from the pretreatment process position to the cleaning process position is 2 meters, the cloth feeding distance from the cleaning tank process position to the amine solution tank process position is 6 meters, the cloth feeding distance from the cleaning tank process position to the amine solution tank process position is 2 meters, the cloth feeding distance from the amine solution process position to the air knife process position is 1 meter, the cloth feeding distance from the amine solution tank process position to the air knife process position is 0.5 meter, the cloth feeding distance from the air knife process position to the TMC solution tank process position is 2 meters, and the cloth feeding distance from the TMC solution tank process position is 0.

The utility model provides a device for producing compound reverse osmosis membrane of polyolefin base, polyethylene micropore base film moves according to the arrow direction from right side to left, and polyethylene micropore base film unreels at unwinding equipment, through pretreatment equipment 30 seconds, and cleaning equipment 2min soaks 3.5% amine solution tank for 30 seconds, and excessive amine solution is detached to the air knife, soaks 0.2% TMC solution tank and carries out interfacial polymerization 30 seconds, obtains polyethylene micropore base film reverse osmosis membrane.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, a plurality of improvements and decorations can be made without departing from the concept of the present invention, and these improvements and decorations should also be considered as within the protection scope of the present invention.

Claims

1. The device for producing the polyolefin substrate composite reverse osmosis membrane is characterized by comprising an unreeling device, a pretreatment tank, a cleaning tank, an amine solution tank, an air knife and a TMC solution tank from the direction of the membrane;