Continuous membrane treatment method for alkali pressed liquid in viscose fiber production process

Abstract

The invention relates to a continuous membrane treatment method for alkali pressed liquid in a viscose fiber production process. The method comprises the steps of material preparation, feeding and system operation. The system operation process further comprises a cleaning step: one stage of nanofiltration membrane assembly is switched out of a nanofiltration membrane system to be cleaned, and other nanofiltration membrane assemblies operate normally; alkali pressed liquid or concentrated liquid generated by the previous-stage nanofiltration membrane assembly skips the nanofiltration membrane assembly being cleaned and is introduced into the next-stage nanofiltration membrane assembly or a concentrated liquid tank; and after cleaning is finished, the nanofiltration membrane assembly is connected back to the nanofiltration membrane system in series again; and each stage of nanofiltration membrane assembly can be separately cleaned in the same manner. The treatment method is a continuousmembrane treatment process with full-automatic operation and cleaning, and a batch intermittent operation mode adopted in a conventional technology is changed, so that the utilization rate of nanofiltration membranes can be effectively improved, the cleaning times of the nanofiltration membranes can be reduced, and the service life of the nanofiltration membranes can be prolonged.

Description

technical field [0001] The invention relates to a continuous membrane treatment method for alkali squeeze liquid in the viscose fiber production process, which belongs to the field of viscose fiber production. Background technique [0002] At present, domestic viscose staple fiber production enterprises generally use nanofiltration membrane system to filter and remove hemicellulose in lye during lye treatment, reduce the content of hemicellulose, and recycle lye. The traditional operation mode is batch batch operation, which is not only time-consuming and labor-intensive, but also needs to be shut down for cleaning once every two tanks of alkali squeeze liquid are processed. Due to this operation mode, the net liquid flux is relatively large at the beginning, but with the concentration of the semi-fiber, the net liquid flux decreases, and the nanofiltration membrane is easy to be fouled, causing attenuation and affecting the filtration effect. Contents of the invention ...

AI Technical Summary

Problems solved by technology

The traditional operation mode is batch batch operation, which is time-consuming and labor-intensive, and needs to be shut down for cleaning once every two tanks of alkali squeezed liquid are processed

Due to this kind of operation mode, the net liquid flux is relatively large at the beginning, but with the concentration of the semi-fiber, the net liquid flux decreases, and the nanofiltration membrane is easy to be fouled, causing attenuation and affecting the filtration effect

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