内压式超滤换向流反洗技术优势

Advantages of Internal Pressure Ultrafiltration Reverse Flow Backwashing Technology

摘要: 根据电力行业的水质特点，电厂广泛采用中水作为除盐水的来水水源，水质相对于地表水而言水质较差，从而需要进行深度预处理。目前深度预处理工艺主要是全膜法工艺流程UF超滤 + 两级反渗透 + 混床工艺，而超滤在系统中发挥着重要的作用，也是保证反渗透稳定运行的关键设备。很多工程大部分采用的外压式超滤，而外压式进水口与反洗口方向固定不能调换，运行周期时间相对较短，且膜污染较严重，经多次反洗后不能完全达到初始状态，对此进行彻底展开分析试验比对，根据水质及工艺系统要求选择适宜的内压式超滤膜，在工艺设计方面通过增加适当的管路与阀门来实现超滤膜进水口与反洗口相互切换(即换向流运行)，分析此系统运行的状况，延长超滤系统运行周期使用时间，减少膜反洗的频次从而提高系统制水率，从而达到节约用水的目的。

Abstract: According to the water quality characteristics of the power industry, power plants widely use reclaimed water as a source of desalinated water. The water quality is relatively poor compared to surface water, so deep pretreatment is needed. Currently, the main deep pretreatment process is the full membrane process UF ultrafiltration + two-stage reverse osmosis + mixed bed process. Ultrafiltration plays an important role in the system and is also a key equipment to ensure the stable operation of reverse osmosis. Many projects use external pressure ultrafiltration, and the direction of the external pressure inlet and backwash outlet is fixed and cannot be changed. The operating cycle time is relatively short, and the membrane pollution is severe. After multiple backwashing, it cannot fully reach the initial state. Therefore, a thorough analysis and experimental comparison are carried out, and suitable choices are selected based on water quality and process system requirements. Internal pressure ultrafiltration membrane, In terms of process design, appropriate pipelines and valves are added to achieve mutual switching between the ultrafiltration membrane inlet and backwash port (i.e. reversing flow operation), analyze the operation status of the system, extend the operating cycle of the ultrafiltration system, reduce the frequency of membrane backwashing, and improve the water production rate of the system, thereby achieving the goal of water conservation.