Interaction of water droplets with pyrolyzing coal particles and tablets  

作　　者：Anastasia Islamova Pavel Tkachenko Pavel Strizhak 

机构地区：[1]National Research Tomsk Polytechnic University,Heat and Mass Transfer Laboratory,30 Lenin Avenue,Tomsk,634050,Russia

出　　处：《Defence Technology（防务技术）》2023年第12期1-12,共12页Defence Technology

基　　金：supported by the Russian Science Foundation (project 18-71-10002-π,https://rscf.ru/en/project/21-71-03001/)。

摘　　要：The paper presents the experimental research findings for the patterns of collisions of water droplets with pressed tableted samples used as substrates and with small particles of a pyrolyzing solid fuel.Brown coal samples were used.Droplet-substrate interactions were studied when varying the droplet diameter in the range from 1 to 4 mm and velocity from 0.5 to 4 m/s.That corresponded to the Weber number range of 7-830.The coal tablet surface temperature was varied from 20 to 700℃.In the interactions of water droplets(0.7-1.5 mm in diameter,pre-collision velocity from 1 to 3 m/s)with coal particles(with a size of 0.2-1 mm,pre-collision velocity 0.7-2 m/s),the temperature of the latter was varied in the range of 330-480℃.The following regimes of the interaction of droplets with solid particles during chemical reactions and phase transformations were distinguished:spreading/agglomeration and break-up/separation.Differences in the characteristics of the interaction of water droplets with coal particles at varying temperatures were identified.Droplet-particle interaction regime maps for B(We),We(Oh)and We(Ca)were constructed.The collision regime boundaries were described using fitted curves that can be utilized to develop the existing mathematical models of droplet-particle collisions in gas.It was established that the gaseous volatile production in coal pyrolysis has a modest effect on the regimes and characteristics of the droplet destruction in the temperature range under consideration(20-700℃).

关 键 词：DROPLET PARTICLE Solid substrate COLLISION AGGLOMERATION Separation 

分 类 号：V31[航空宇航科学与技术—航空宇航推进理论与工程] V51