循環乾燥模式中之稻穀減乾率、碾整率與乾燥熱效率

Drying Rate, Head Yield and Drying Efficiency of Paddy Rice-In Recirculating-Pattern Drying

陳貽倫(Yi-Luen Chen)

《農業機械學刊》 2卷3期 (1993/09) Pp. 1-10

https://doi.org/10.30062/JAM.199309.0001

摘要

本文以一稻穀樣品乾燥機模擬循環乾燥模式，每次乾燥12個樣品，以2×2×3複因子設計進行試驗。每次乾至近14% (wb)為止。乾後之稻穀予以脫殼、碾米並選出整粒米。外界乾濕球溫度、乾燥用熱風之溫度、風量、每回之減乾水分等分別予以記錄，並據以計算乾燥所需熱量、穀物蒸發潛熱、減乾率及乾燥熱效率。結果顯示：所有三種因子－通風量、每回乾燥時間及熱風溫度－對減乾率、碾整率及熱效率均具有顯著效應，但對熱效率而言，只有通風量有顯著效應。任兩種通風量之一，再加以每回10分鐘乾燥時問和40℃熱風溫度之組合條件下，稻穀乾後碾米，顯示其未損及碾整率，而在其他乾燥條件下，則各有不同程度之碾整率損失。平均乾燥熱效率在43%和56%之間，但乾燥初期熱效率可達100%以上，末期則可低於10%。

關鍵字

稻穀 ； 乾燥 ； 整粒米 ； 熱效率

並列摘要

A 2×2×3 factorial drying experiment, simulating recirculating drying pattern, was carried out in a rice-sample dryer, which can dry 12 samples at a time. The dying stopped when the rice molsture content approached 14% (wb). The dried rice samples were then hulled, milled, and sorted for head rice. The temperatures of the ambient air, the drying air, the moisture reduction at each drying stage were recorded, thereby the energy consumptions, the latent heat of grain moisture evaporation, the drying thermal efficiency, and drying rate were calculated.
The resulted data showed that all three drying factors-drying air flow rate, drying time duration, and drying air temperature-had significant effects on drying rate, and head yield, but only the air flow rate affected drying thermal efficiency.
Under both 0.23 CMM/kg and 0.30 CMM/kg flow rate conditions, the combination of 10 minutes per cycle drying with 40℃drying air temperature did not cause head yield loss, while the other treatments resulted in losses of different extents.
Average drying thermal efficiency ranged from 43 to 56%, but the efficiency can be over 100% at the first stages of drying, and lower than 10% at the finals.

並列關鍵字

Rice ； Drying ； Head yield ； Thermal efficiency