| 摘要: | 由於人類經常會需要將顆粒儲存，使得儲槽是現代工業和農業中不可或缺的設備之
一，對於確保有效的原料管理、提高生產效率和確保產品質量至關重要。在進行相關研
究時，儲槽的設計和性能對於確保這些方面的有效性具有重要作用。而儲槽邊壁的特性，
如表面材料、粗糙度等，被證明在影響流體行為、排放性能等方面發揮著至關重要的作
用。
本研究使用類二維儲槽裝置，透過儲槽不同部分邊壁置換為類軸承，且變換儲槽半
角，並於實驗時填入固定重量圓柱顆粒進行排放。其中為了瞭解類軸承邊壁對不同顆粒
長度變化的影響，本研究利用直徑 dP = 4mm 而長度 dL 分別是 4mm、8mm 以及 12mm
的三種不同長度之 ABS 塑膠圓柱。本研究透過安息角實驗及摩擦角實驗來量測各顆粒
體的基本性質，以及與邊壁之間的摩擦效應。在儲槽卸料實驗過程中，則使用高速攝影
機進行影像拍攝，透過粒子影像測速技術 PIV (particle image velocimetry)和 MATLAB 進
行後續影像處理。此外，利用研究平均質量流率、速度場及停滯區，來了解置換邊壁為
類軸承對於整體流動性的影響和成效。
實驗結果顯示，將儲槽邊壁置換為類軸承邊壁確實會影響整體顆粒排放，質量流率
的改善會因為使用較長顆粒(圓柱顆粒長度與類軸承滾柱外徑的長徑比 R 較大)而更為顯
著，且漏斗半角越小則改善趨勢越明顯。本研究將各種類軸承邊壁安裝類型的儲槽內圓
柱顆粒排放改善情況與長徑比及漏斗半角的關係繪製成排放改善相圖，有明顯改善區、
過渡區及惡化區等三種改善相態，結果顯示全部安裝類軸承邊壁的排放改善相圖會與僅
漏斗部更換類軸承邊壁的改善相圖完全相同，表示漏斗部的類軸承邊壁之影響最大。另
外，明顯改善區的速度場會因為安裝類軸承邊壁，而使得出口速度明顯較大，且停滯區
縮小，進而使儲槽內顆粒的流動更趨向於質量流。
;Since humans often need to store granular materials, storage silos have become
indispensable equipment in modern industry and agriculture, crucial for ensuring effective raw
material management, enhancing production efficiency, and maintaining product quality. The
design and performance of silos play a significant role in ensuring these aspects. The
characteristics of silo walls, such as surface material and wall friction, have been shown to
critically affect fluid behavior and discharge performance.
This study used a quasi-2D silo device, where different parts of the silo walls were replaced
with roller sidewall, and the half-angle of the silo was varied. Fixed-weight cylindrical particles
were filled for discharge during the experiments. To understand the impact of bearing-like walls
on particles of different lengths, ABS plastic cylinders with a diameter of dP = 4mm and lengths
of dL = 4mm, 8mm, and 12mm were used. The basic properties of each particle and the friction
effects between the particles and the walls were measured through repose angle experiments
and friction angle experiments. During the silo discharge experiments, high-speed cameras
were used to capture images, and subsequent image processing was performed using particle
image velocimetry (PIV) and MATLAB. Additionally, by studying the average mass flow rate,
improvement rate phase diagrams, velocity field, and stagnant zones, the impact and
effectiveness of replacing the walls with roller sidewall on overall flowability were understood.
The experimental results show that replacing the silo walls with roller sidewall indeed
affects the overall particle discharge. The improvement in mass flow rate is more significant
when using longer particles (with a larger length-to-diameter ratio R of cylindrical particles to
the outer diameter of the rollers), and the improvement trend is more pronounced with a smaller
hopper half-angle. This study plots the discharge improvement phase diagram for cylindrical
particle discharge in silos with various types of bearing-like wall installations, showing the
relationship between the length-to-diameter ratio and the hopper half-angle. There are three
improvement phases: improvement region, transition region, and deterioration region. The
results indicate that the discharge improvement phase diagram for fully installed roller sidewall
is identical to that for replacing only the hopper section with roller sidewall, suggesting that the
roller sidewall of the hopper section have the greatest impact. Additionally, in the significant
improvement zone, the velocity field is noticeably increased due to the installation of bearing like walls, the stagnant zone is reduced, and the particle flow within the silo tends more towards
mass flow. |
