木屑於貯槽中排放速率之研究

The Study of Sawdust Mass Flow Rate from Bins

莊富雄(Fu-Hsiung Chuang)

指導教授 ： 錢建嵩

中原大學/工學院/化學工程學系/碩士(2006年)

https://doi.org/10.6840/CYCU.2006.00421

摘要

一般重力排放的的貯槽，在某些粉體排放的過程中可能出現架橋或是漏斗流動等問題，架橋現象會嚴重影響粉體的操作程序，而較差的流動方式容易引起粉體發生鼠洞、固化、崩落、奔流或離析等現象，進而影響粉體排放的穩定性。
本篇研究對於木屑進料槽排放過程進行研究，實驗中所採用的參數為漏斗槽側向注吹空氣的位置、注吹空氣流量、孔口大小、木屑形狀、粒徑大小和床重，對於側向注吹下木屑的排放速率、木屑的流動型態及是否可有效破壞架橋現象等做探討。觀察實驗結果可發現：木屑形狀對排放速率有很大的影響，所使用木屑粒徑越大或形狀為針狀時，注吹位置需越接近出口處且流量需越大才能有效破壞架橋。而當木屑為較小之顆粒狀材料時，於漏斗槽較高處注氣，可獲得較快之排放速率，填充此類粒子時，不論注吹位置的高低，皆可得到穩定的排放速率，流動型態趨向整體流動(mass flow)。

關鍵字

貯槽 ； 漏斗槽 ； 排放速率 ； 木屑 ； 架橋

並列摘要

The arching and funnel flow are two frequently encountered problems on the powder discharge from a gravity-flow hopper. The influence of arching on the operation procedure is significant in ratholing, consolidation, spoilage, flooding, and segregation. These phenomena further lead to unstable powder discharge from bins.
This work investigates the sawdust discharging process from feed tanks. The sawdust mass flow rate, the flow patterns and arching phenomena were observed after introducing the aerating gas near the orifice with the operating parameters of aeration height, volume flow rate of air, the size of orifices, the shape of particles, the particle size, and bed weight. The experiment results show that a larger size or acicular shape of sawdust has greater influence on the mass flow rate of sawdust. In order to eliminate the arching phenomenon, the aerating gas needs to be introduced possibly close to the orifice with a high flow rate. When sawdust is in a small granular shape, a higher aerating gas introducing position obtains a faster mass flow rate. In addition, packing with this shape of particles, no matter where the introducing position of the aeration gas is. The mass flow rate will be steady, and the flow pattern tends to be the mass flow type.

並列關鍵字

sawdust ； mass flow rate ； bin ； hopper ； arching

參考文獻

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