摘要
考察了二甲基甲酰胺中的盐在换热器换热冷却过程中的结垢行为,分别采用内置弹簧和液固流态化以及两者结合的方法对换热器在线防垢除垢进行研究。采用测定总传热系数法研究污垢热阻随时间的变化规律,并用污垢称重法测定不同条件的总污垢量。研究了流体流速、传热温差、弹簧结构、惰性固体颗粒数量和大小等诸因素对结垢的影响,结果表明:直径与管内径比为0.8,螺距和管内径比为1.5的弹簧在0.6～1.0m·s-1的流速范围内防垢除垢效果最佳,随着颗粒数量的增加和粒径的增大,污垢生成速率降低,结垢量减少,相比同条件下单纯颗粒流态化除垢,内置弹簧和颗粒流态化结合法可以使污垢量减少20%～50%。实验研究结果对实际的工业过程具有一定的参考意义和指导价值。
The fouling behavior of mixed salts in DMF （N,N-dimethylformarnide） solution during cooling in heat exchanger was investigated. The methods of inserting screw spring in the cooling tube, putting solid particles in the cooling tube to form liquid-solid fluidization and the combination of these two measures were adopted respectively to prevent and clean up the fouling scale on the tube wall on-line. The variation of the heat transfer resistance of fouling scale with cooling time was obtained by total heat transfer coefficient method, and the total amount of mixed salts crystallization fouling was measured by weighting method. The effects of fluid velocity, temperature difference of cooling, structure parameters of inserted spring, number and size of solid particles putted in the tube on the fouling scale formation were studied. The results show that, in the fluid velocity range of 0.6-1.0 m·s^-1, the inserted spring has the best anti-fouling effect when the ratios of its diameter and screw-pitch to the tube inside diameter are 0.8 and 1.5, respectively; And for the liquid-solid fluidization method, the scale forming rate and the weight of fouling scale formed in certain time decrease with the increase of the particle number and particle size. For the combination method of combining the inserting spring and adding solid particle to form liquid-sold fluidization method, the weight of fouling scale formed in certain time can be decreased by 20%-50% of that formed by using the liquid-solid fluidization method alone under the same experimental condition. The results could be used as reference and guide for the actual industry process.
出处
《高校化学工程学报》
EI
CAS
CSCD
北大核心
2009年第1期51-56,共6页
Journal of Chemical Engineering of Chinese Universities
关键词
二甲基甲酰胺
防污垢
换热器
液固流态化
内置弹簧
N,N-dimethylformamide
anti-fouling
heat exchanger
liquid-solidfluidization
inserted spring
