Electrodeionization method and electrodeionization device with enhanced scale prevention effect

Abstract

The invention discloses an electrodeionization method and an electrodeionization device with an enhanced scale prevention effect. According to the method, a fresh water flow is in a one-stage two-section flow, a concentrated water flow is a one-stage one-section flow, and the concentrated water flow and the fresh water flow in the first flow of the fresh water flow can generate mutual reflux effect. The electrodeionization device comprises an anode plate, an anode chamber partition board, n repeatable basic working units, one basic working unit, m repeatable basic working units, one basic working unit and a cathode plate which are sequentially stacked together, wherein a fresh water flow partition board in the basic working unit is replaced with a fresh water reversing partition board, a concentrated water flow partition board in the other basic working unit is replaced with a cathode chamber partition board, n and m are integers, and m is more than or equal to 1 and less than or equalto n. According to the electrodeionization method and an internal water flow design and an operation process in the device, the electrodeionization desalting can be realized without scaling under inflow hardness of 5mg / L-10mg / L, meanwhile, the device can well resist water quality fluctuation of inflow and simultaneously has enhanced scale prevention effect and high operational stability.

Description

technical field [0001] The invention relates to a method and device for desalting water, in particular to an electrodeionization method and device for deep desalination to prepare high-purity water with enhanced anti-scaling performance, belonging to the technical field of energy saving and environmental protection. Background technique [0002] Electrodeionization (EDI for short), originally called packed bed electrodialysis, is an electrically driven membrane separation technology that organically combines ion exchange resin and electrodialysis. EDI is to fill the ion exchange resin in the fresh water chamber of electrodialysis with increased thickness. Under the action of DC electric field, the positive and negative ions in the water of the fresh water chamber move toward the negative electrode and the positive electrode respectively along the ion channel formed by the ion exchange resin and the ion exchange membrane. Migration, cations selectively pass through the cation...

AI Technical Summary

Problems solved by technology

More importantly, for a considerable number of existing industrial high-purity water systems that adopt the "one-stage RO-mixed bed ion exchange" process, since the pre-treatment is only one-stage RO, the quality of the produced water cannot meet the influent requirements of EDI. As a result, EDI cannot be directly used to replace the downstream mixed-bed ion exchange equipment; and if the upstream RO process is upgraded to a two-stage RO, it will not only require a significant increase in investment, but also often does not have the conditions for transformation in terms of site and other aspects

Therefore, although EDI is theoretically a more advanced, efficient and environmentally friendly deep desalination technology, its share in the pure water technology market is still less than 10%

[0011] It can be seen that the existing EDI technology has not been able to provide a feasible technical solution, enabling it to effectively relax the hardness limit of the incoming water, and at the same time improve the operation stability of EDI against fluctuations in raw water quality, and provide completely independent and isolated electrode water pipelines , to ensure the operational safety of EDI and the entire water treatment system

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