关键词: 机械蒸汽再压缩技术, 干燥, 压缩机, 模型, 干燥动力学, 干燥方程

Abstract: Based hollow paddle dryer set up a mechanical vapor recompression heat pump vacuum drying system.The vacuum pressure was about 95kPa, the same mass of sludge(100±0.1)kg at a constant temperature drying experiment at 95-115℃.Get the moisture content of the sludge drying process curves and drying rate curves.The outlet steam temperature of the compressor was 95-115℃, and the critical moisture content of the sludge was increased from 0.22 to 0.34.Five kinds of sludge drying models were introduced.The experimental data were segmented fitting analysis by using origin software and obtain sludge drying kinetics model MR=exp(-ktⁿ), Dried equation with piecewise function expressed respectively:MR=exp[-(2.78×10^-4T-0.01896)t^1.596](acceleration phase);MR=0.894-0.564(1.74×10^-4T-8.05×10^-3)t(constant speed phase);MR=exp[-(2.26×10^-4T-0.01365)t^1.984](deceleration phase).The drying model was verified by experiments, the average relative error of wet content of sludge in each drying stage was calculated, and the resulting experimental drying curves and drying rate curves were compared with the predicted values. It can be seen that the segmentation process can better describe the sludge drying law.

Key words: mechanical vapor recompression, drying, compressor, model, drying kinetics, drying equation