粮食与油脂
糧食與油脂
양식여유지
CEREALS & OILS
2014年
4期
52-56
,共5页
稻谷%氮气%扩散%微环境
稻穀%氮氣%擴散%微環境
도곡%담기%확산%미배경
paddy%N2%dispersion%microenvironment
在模拟仓内装满稻谷后,埋入5层3列N2传感器,从仓底进气口充入流速为10 L/min的N2,时间约为70 min,室内温度20℃,关闭N2气源后测定氮气浓度至300 min,研究氮气的自由扩散规律。结果表明:在充气阶段,距离进气口越近的点的氮气浓度上升越快;在同一层面上,以进气口所在处对称的点浓度比较接近,可以由已知点的浓度来判断未知点的浓度;由于氮气密度较空气小,氮气在纵向传递的速率高于横向传递的速率15%~25%。氮气的扩散速率在充气的过程中与进气口的距离呈正相关,在自由扩散过程中,靠近粮面的氮气可以维持在一个比较恒定的速率(0.05%/min),下层氮气扩散速率最快(约为0.2%/min),中层的次之(约为0.09%/min)。粮堆内各层之间具有显著性相关,而受到氮气密度的影响下层和中层的相关性要高于中层和上层;距离进气口越远的层,氮气的浓度变化越为稳定。
在模擬倉內裝滿稻穀後,埋入5層3列N2傳感器,從倉底進氣口充入流速為10 L/min的N2,時間約為70 min,室內溫度20℃,關閉N2氣源後測定氮氣濃度至300 min,研究氮氣的自由擴散規律。結果錶明:在充氣階段,距離進氣口越近的點的氮氣濃度上升越快;在同一層麵上,以進氣口所在處對稱的點濃度比較接近,可以由已知點的濃度來判斷未知點的濃度;由于氮氣密度較空氣小,氮氣在縱嚮傳遞的速率高于橫嚮傳遞的速率15%~25%。氮氣的擴散速率在充氣的過程中與進氣口的距離呈正相關,在自由擴散過程中,靠近糧麵的氮氣可以維持在一箇比較恆定的速率(0.05%/min),下層氮氣擴散速率最快(約為0.2%/min),中層的次之(約為0.09%/min)。糧堆內各層之間具有顯著性相關,而受到氮氣密度的影響下層和中層的相關性要高于中層和上層;距離進氣口越遠的層,氮氣的濃度變化越為穩定。
재모의창내장만도곡후,매입5층3렬N2전감기,종창저진기구충입류속위10 L/min적N2,시간약위70 min,실내온도20℃,관폐N2기원후측정담기농도지300 min,연구담기적자유확산규률。결과표명:재충기계단,거리진기구월근적점적담기농도상승월쾌;재동일층면상,이진기구소재처대칭적점농도비교접근,가이유이지점적농도래판단미지점적농도;유우담기밀도교공기소,담기재종향전체적속솔고우횡향전체적속솔15%~25%。담기적확산속솔재충기적과정중여진기구적거리정정상관,재자유확산과정중,고근량면적담기가이유지재일개비교항정적속솔(0.05%/min),하층담기확산속솔최쾌(약위0.2%/min),중층적차지(약위0.09%/min)。량퇴내각층지간구유현저성상관,이수도담기밀도적영향하층화중층적상관성요고우중층화상층;거리진기구월원적층,담기적농도변화월위은정。
After the paddy rice was filled,within the simulation silo,nitrogen sensors were buried (in the form of 5×3). The nitrogen was charged through the inlet,which was located at the bottom of the silo,and the flowrate was 10 L/min. The charging time was 70 min,approximately,and the ambient temperature was 20℃. As the inlet valve was switched off,the concentration of nitrogen was monitored,for the sake of studying free diffusion of nitrogen. The results demonstrate that,during the aeration stage,the concentration of nitrogen increased as the distance between the checking point from the inlet decreased. At the same layer,due to concentrations of symmetrical points of inlet were relatively close,unknown figures could be deduced by the concentration which was recorded. Since the density of nitrogen is smaller than the air,the vertical flowrate was faster than the horizontal one, at about 15~25%. In addition,during the charging,there was a positive correlation between diffusion rate of nitrogen and the distance to the inlet. The flowrate of nitrogen closing to the surface of grain stayed relatively constant,at about 0.05%/min,during the free diffusion. The fastest rate was found at the bottom(around 0.2%/min),followed by middle’s(about 0.09%/min). Layers in the pile held significant correlations. It should be noted that the correlation between bottom and middle was much tighter than the one between middle and top. This is probably due to the influence of density of nitrogen. What is more,there was a tendency that the concentration of nitrogen became stable as the layer farther to the inlet.