Abstract

Industrial gas dehumidification contributes to a considerable portion of the total industrial energy consumption. Depending on the desired level of dryness, solid desiccants can be a more suitable dehumidification method compared to the conventional dehumidification processes. In this study, the ultrasound-enhanced regeneration of silica gel as a substitute to conventional heating methods is investigated. To analyze the energy-savings effect of applying ultrasound a method of constant total power levels of 20 and 25 (W) corresponding to total specific power levels of 327 and 409 $(\mathrm{W}/{\mathrm{kg}}_{\mathrm{SG}})$ was adopted and for each Watt of applied ultrasonic power, the same amount was deducted from thermal power. The moisture content and regeneration temperature were measured and compared in ultrasound-assisted and non-ultrasound (heat-only) regeneration processes. Experimental results showed that applying ultrasound along with thermal power improves the regeneration process and reduces the energy required to regenerate silica gel by as much as 26%. Various transport modes contributing to mass diffusion in porous media are analyzed and an apparent diffusion coefficient for porous media that includes ultrasonication effects is proposed. Regarding regeneration temperature, with application of ultrasound, regeneration at lower temperatures by as much as ∼11% was achieved.

摘要

工业气体除湿占整个工业能源消耗的很大一部分。根据所需的干燥程度，与传统的除湿过程相比，固体干燥剂可能是更合适的除湿方法。在这项研究中，研究了替代传统加热方法的硅胶的超声增强再生。为了分析应用超声波的节能效果，采用恒定总功率水平为 20 和 25 (W) 的方法对应于总比功率水平为 327 和 409$(\mathrm{W}/{\mathrm{公斤}}_{\mathrm{SG}})$被采用，并且对于施加的每瓦超声波功率，从热功率中扣除相同的量。在超声辅助和非超声（仅加热）再生过程中测量和比较了水分含量和再生温度。实验结果表明，应用超声波和热能改善了再生过程，并将再生硅胶所需的能量降低了 26%。分析了影响多孔介质质量扩散的各种传输模式，并提出了包括超声作用在内的多孔介质表观扩散系数。关于再生温度，通过应用超声波，在较低温度下的再生率达到了 11%。