Abstract Particle deposition and fouling mainly hamper the applicability of porous membranes in filtration applications. Temperature has rarely been investigated or even used to manipulate deposition behavior at membranes and to increase membrane performances although strongly affecting the transport phenomena in and at membrane surfaces. Temperature modulates the hydrodynamic properties, the interaction between solutes and surfaces, and the molecular structure of particles. In this study, we present a novel approach to influence membrane performances and particle deposition by direct membrane heating. Novel inorganic porous hollow fiber membranes made from silicon carbide are directly heated by Joule heating using the electrical resistance of the membranes. The direct heat supply is used during yeast filtration for in-place membrane cleaning and advanced backwashing. Three different approaches are tested: (i) Power application of 70 W m−1 during permeation in cross-flow operation, (ii) 30 W m−1 during permeation in dead-end operation and (iii) 30 W m−1 during backwash operation after unheated dead-end permeation cycles. The power application features temperatures of 50 ∘ C. The localized heating of the boundary layer at the surface of the membrane reduces the energy requirement by 40% compared to complete feed heating for the cross-flow configuration as the large feed stream remains partially unaffected. The viscosity-corrected fouling resistance of the membranes during heated permeation can be decreased by 27–31% in dead-end and cross-flow filtration through the heat treatment, respectively. We contribute the effect to small changes in shear induced cleaning by the thermal treatment. Membrane heating during backwashing results in a 30% reduction of the resistance over a course of 11 permeation–backwashing cycles compared with conventional backwashing.

中文翻译：

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直接膜加热以防止温度引起的结垢

摘要 颗粒沉积和污垢主要阻碍了多孔膜在过滤应用中的适用性。尽管温度会强烈影响膜表面内和膜表面的传输现象，但很少研究甚至使用温度来操纵膜上的沉积行为并提高膜性能。温度调节流体动力学特性、溶质和表面之间的相互作用以及粒子的分子结构。在这项研究中，我们提出了一种通过直接膜加热影响膜性能和颗粒沉积的新方法。由碳化硅制成的新型无机多孔中空纤维膜利用膜的电阻通过焦耳热直接加热。在酵母过滤过程中使用直接供热进行原位膜清洁和高级反冲洗。测试了三种不同的方法：(i) 横流操作中渗透过程中施加 70 W m-1 的功率，(ii) 末端操作中渗透过程中 30 W m-1 和 (iii) 过程中 30 W m-1未加热的死端渗透循环后的反冲洗操作。功率应用的特点是温度为 50 ∘ C。与完全进料加热相比，膜表面边界层的局部加热使能量需求减少了 40%，因为大进料流部分不受影响。通过热处理，膜在加热渗透过程中的粘度校正抗污染性可以分别在死端过滤和错流过滤中降低 27-31%。我们通过热处理对剪切诱导清洁的微小变化做出了贡献。与传统反冲洗相比，反冲洗过程中的膜加热在 11 次渗透-反冲洗循环过程中使阻力降低了 30%。