摘要
为了提高脉冲式布袋除尘器灰尘颗粒的沉降效率及布袋的使用寿命,基于动能耗散的设计思路对进气道结构进行改进。利用数值模拟手段,研究改进前后进气动能耗散对布袋除尘器内部流场的影响,并采用DPM方法评价灰尘颗粒在布袋除尘器中的运动状态及沉降效率。结果表明:改进后的布袋除尘器流场更加稳定,灰斗底部的最大气流速度由原来的19.2 m·s^(-1)降至9.6 m·s^(-1),中箱体底部的最大气流速度由原来的24.4 m·s^(-1)降至9.3 m·s^(-1);改进前后设备阻力无显著差异;通过对不同粒径的灰尘颗粒沉降率比较发现,改进后的布袋除尘器对于100、150、200、250和300μm灰尘颗粒的沉降率分别提高了11.4%、38.9%、59.6%、69.0%和71.6%。这表明耗散箱结构能够通过合理消耗进气动能降低设备关键区域的气体动能,从而减少了二次扬尘的产生和含尘气体对布袋的冲刷。上述数值模拟结果可为脉冲式布袋除尘器的流场设计提供理论依据。
In order to improve the settling efficiency of dust particles and the service life of the bags in pulse-jet bag filter,the intake duct structure was optimized based on the concept of kinetic energy dissipation.The impact of intake kinetic energy dissipation on the internal flow field of the pulse-jet bag filter was studied by using numerical simulation methods.The Discrete Phase Model was employed to evaluate the motion states and settling efficiency of dust particles in the bag filter.The results indicated that the flow field of the modified pulse-jet bag filter was more stable.The maximum airflow velocity at the bottom of the hopper decreased from the original 19.2 m·s^(-1)to 9.6 m·s^(-1),and the maximum airflow velocity at the bottom of the middle casing decreased from the original 24.4 m·s^(-1)to 9.3 m·s^(-1).There was no significant difference in equipment resistance before and after the modification.Comparisons of the settling rates of dust particles with different diameters revealed that the settling rates of dust particles with diameters of 100,150,200,250 and 300μm increased by11.4%,38.9%,59.6%,69.0%and 71.6%,respectively,after the modification.The results indicated that the dissipation box structure,by reasonably consuming the kinetic energy of the intake air,reduced the gas kinetic energy in critical areas of the device.Thereby,it can inhibit the dust which is blown up repeatedly and weaken the impact of dusty gases on the bags.The numerical simulation results can provide theoretical basis for the flow field design of pulse-jet bag filter.
作者
李鹏龙
郑镭
韩炬
范云明
郑玮熙
陆广军
LI Penglong;ZHENG Lei;HAN Ju;FAN Yunming;ZHENG Weixi;LU Guangjun(College of Mechanical Engineering,North China University of Science and Technology,Tangshan 063210,China;Tangshan Dunshi Construction Engineering Co.,Ltd.,Tangshan 064000,China)
出处
《环境工程学报》
CAS
CSCD
北大核心
2024年第7期1945-1957,共13页
Chinese Journal of Environmental Engineering
基金
河北省自然科学基金资助项目(E2019209153)
唐山市应用基础研究资助项目(22130219G)。
关键词
脉冲式布袋除尘器
数值模拟
动能耗散
布袋寿命
沉降效率
pulse-jet bag filter
numerical simulation
kinetic energy dissipation
bag life
settling efficiency
