Delft University of Technology, Department of Civil Engineering, Stevinweg 01, 2628 CN, Delft, The Netherlands.
Delft University of Technology, Department of Civil Engineering, Stevinweg 01, 2628 CN, Delft, The Netherlands.
Water Res. 2016 Dec 1;106:232-241. doi: 10.1016/j.watres.2016.10.012. Epub 2016 Oct 5.
It is widely accepted that our understanding about the membrane process increases by investigation of the hydraulic conditions of membranes. While numerical studies have been broadly used for this purpose, the experimental studies of a comparable resolution are scarce. In this study, we compared the pressure drop, the temporal and the spatial velocity maps of a spacer-filled channel and an empty channel of the same size to determine the effect of presence of the feeds spacer on hydraulic conditions. The velocity maps are obtained experimentally by using of the Particle Image Velocimetry (PIV) technique. Application of the feed spacer caused 2-8.5 higher pressure drop increase in the experimental conditions in this research. The flow had a spatial distribution in the form of a unimodal symmetric curve of normal distribution in the empty channel and a bimodal asymmetric curve in the spacer-filled channel. The bimodal curve indicates the presence of high- and low-velocity zones. Additionally, the low-velocity zones showed also a lower variation of velocity in time, which indicates the high fouling potential of these locations. The results from this study may be uses for validation of numerical studies.
人们普遍认为，通过研究膜的水力条件，可以加深我们对膜过程的理解。虽然已经广泛使用数值研究来达到这一目的，但具有类似分辨率的实验研究却很少。在这项研究中，我们比较了具有相同尺寸的填充有隔片的通道和无隔片的通道的压降、时变和空间速度图，以确定进料隔片的存在对水力条件的影响。速度图通过使用粒子图像测速（PIV）技术实验获得。在本研究的实验条件下，进料隔片的应用导致压降增加了 2-8.5 倍。在无隔片的通道中，流动呈现出单峰对称的正态分布形式的空间分布，而在填充有隔片的通道中则呈现出双峰不对称的曲线。双峰曲线表明存在高速区和低速区。此外，低速区的速度随时间的变化也较小，这表明这些位置的结垢潜力较高。本研究的结果可用于数值研究的验证。
