Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/35747
標題: 稻穀密閉式平倉冷藏之研究
Study on Cold Storage of Rice in a Flat Bin
作者: 白瀛洲
Pai, Chouying
關鍵字: Flat Bin;平倉;Cooler;Rice;冷藏機;稻穀
出版社: 農業機械工程學系
摘要: 
This study is focused on the storing characteristics of a flat bin with concrete base located at Tien-Chung warehouses, the Changhua farmers' association. This bin, previously equipped with a naturally ventilating system, was then replaced by a closed cooling system for experiment. The effects on the rice quality will then be examined and studied as follow:
For the empty (no load) condition, an airflow rate of 9.28 m3/ton-hour was measured, which fairly meets the requirement for a cool storage of paddy. Only less variations of temperature distribution inside the empty bin were found at the beginning and the temperatures at each checkpoint became steadier as the bin further regains ambient heat.
At the front of entrance, the ambient air was constrained in small holes and can only enter at a less speed. The wind speed at the rear end will be 2.3 times higher than that at the front The surface wind speed is found linearly related to the distance from the front end, with an correlation coefficient of 0.84.
For the experiment with paddy in a cooling storage, the temperature of grain at the bottom level has shown less decreasing, which reveals that the airflow is comparatively lower in this section. At the start of cooling process, it requires a longer cooling period to get rid of more heat. Throughout the experiment, the temperatures of grain have changed dramatically. The reasons are that the cooling process has been performed in an intermittent manner and the grain surface was not even spread well to get an even grain depth.
As to the grain quality during the storage, it has exhibited an obvious change in moisture content, it changes greater for the second period than for the first one. However, the result of constant samplings shows that the germination rate and milling rate of paddy does not have any significant difference from the conventional one, which concludes that paddy stored in a closed cooling bin can maintain its good quality.

本論文以國內水泥平倉為對象,將原有通自然風的散裝貯藏方式改為閉密式平倉之通冷風系統後,研究其對稻穀散裝貯藏特性及貯藏後品質的影響,並實地於彰化縣農會田中倉庫進行試驗,試驗結果如下:
在空倉測試方面:通冷風系統之單位通風量約為9.28 (m3/ton-hr),符合平倉冷藏稻穀時之降溫要求。各量測點溫度分佈之差異程度僅有微小的變化,且在回溫過程中各點溫度更趨於一致。但通風槽前端的沖孔處風速則較小,後端的風速為前端的2.3倍,表面風速與距前端的距離呈線性正比關係,相關係數約為0.84。
在稻穀冷藏方面:平倉穀堆下層角落及中心的穀溫降溫速率明顯較低,顯示這些位置之通風量亦較低。於第一次通冷風作業時,若通風時間不足,則無法排除穀堆餘熱。在全程冷藏監控結果發現穀堆的溫度起伏很大,原因與通風採間歇式、穀層表面未掃平及穀層厚度不足有關。
在稻米品質方面:稻穀於冷藏期間稻穀的含水率有明顯的變化,且第二期的變化較第一期大。利用平倉進行稻穀散裝冷藏過程中,定時取樣分析結果,在冷藏過程中稻穀發芽率及碾米率等並無顯著差異,因此採平倉散裝冷藏稻穀,能確保稻米的良好品質。
URI: http://hdl.handle.net/11455/35747
Appears in Collections:生物產業機電工程學系

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