前置碱雾发生器内气液固多相流动的测量研究

Velocimetric Study of Gas-solid Multiphase Flow in Topping Alkaline Atomizers

根据两相流相似模化原理建立了前置碱雾发生器烟气脱硫颗粒图像测速技术多相流动实验台,运用颗粒图像测速(PIV)技术对前置碱雾发生器内气液固三相流动进行测量,得到不同工况条件下喷雾射流与固体颗粒的流动结构和流场信息。结果表明:由于雾化液滴射流的卷吸作用,大部分固体颗粒被卷吸进雾化锥内,在喷嘴出口一定区域固体颗粒与雾化液滴具有较大的速度差,在雾化锥内固体颗粒与雾化液滴发生剧烈的碰撞形成浆液,此为形成碱雾的主要区域。合理设计边壁风量有利于抑制甚至防止雾化液滴以及碰撞形成的浆滴可能的粘壁现象。

Based on simulation principles of two-phase flow, a test rig has been set up for studying multi-phase flow, during flue gas desulfurization, in topping alkaline atomizers. Gas-droplet-solid three phase flow was studied by particle image velocimetry （PIV）, obtaining herewith pictures of relevant flow structure, as well as flow field information, concerning the jet and the particles under different operating conditions. Results show that most solid particles are being drawn into the atomizing cone by sucking action of the atomizing jet; the velocity difference between solid particles and droplets, in a certain range behind the nozzle opening, causes hefty collisions between solid particles and atomized droplets, wherewith slurry is formed. This is the main region where alkaline mist appears. Rationally designing wall bordering flow helps to reduce, or prevent, the atomized droplets and slurry droplets, formed by collision, to adhere to the walls. Figs 8 and refs 6.