Method and device for manufacturing nanofiltration membrane

Abstract

The invention belongs to the technical field of nanofiltration membranes. More specifically, the invention relates to a manufacturing method and device. The invention provides equipment and method forpreparing a nanofiltration membrane base membrane on a large scale. The uniformity of the base membrane and the stability of continuous operation in the large-scale preparation process can be improved, the high-flux nanofiltration membrane base membrane with a stable structure is continuously prepared, and a uniform reaction carrier is provided for preparation of a composite nanofiltration membrane.

Description

technical field [0001] The invention belongs to the technical field of nanofiltration membranes. More specifically, the present invention relates to a manufacturing method and device. Background technique [0002] Due to its high efficiency, low energy consumption and high selectivity, membrane technology has become a key technology to solve water shortage and pollution, and has been widely used around the world. Nanofiltration is a new membrane separation technology between ultrafiltration and reverse osmosis, with a molecular weight cut-off in the range of 100-2000 Daltons. The pore size of nanofiltration is in the range of 0.5-2nm, which has the comprehensive characteristics of pore size repulsion and charge interaction, and has great prospects in the field of separation of small organic molecules and multivalent salts. [0003] The nanofiltration composite membrane is composed of two parts: one part is a porous base film layer for support; the other part is a thinner d...

AI Technical Summary

Problems solved by technology

Since the polyamine aqueous solution is a water-soluble monomer dissolved in water and has low viscosity, the general aqueous phase coating process can only be coated by dip coating, while the traditional dip coating roll type is in the form of a single roll, and the roll diameter is fixed size, it is impossible to adjust the dipping time of the water phase and the removal of excess polyamine aqueous solution on the surface of the base film according to the change of the hydrophilicity of the base film layer material and the change of the preparation environment

Generally, the water-phase dipping time can be adjusted by changing the diameter of the coating roller, but this method is costly, and the diameter of the roller increases, and the processing and installation accuracy are difficult to guarantee.

Existing production equipment is difficult to meet the large-scale production requirements of polyamide flat nanofiltration membrane

[0005] In addition, the organic phase monomer solution changes with time due to the reaction with the polyamine monomer in the water phase, resulting in unstable product quality; secondly, the diffusion of the organic phase in the basement membrane structure is affected by the viscosity, density, gravity, and Due to the influence of properties such as hydrophilicity, the degree of diffusion directly affects the reaction process of interfacial polymerization and thus affects product performance. Existing processes and equipment cannot be effectively adjusted according to changes in the material system to stabilize product performance; again, the organic phase The reaction time with the polyamine aqueous phase monomer cannot be adjusted according to different process requirements, making it difficult for the existing device technology to meet the requirements of large-scale continuous production

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