绿麦芽喷动干燥技术研究  

Technology for spouted bed drying of green malt

作　　者：刘伟民[1] 李小果[1] 陈健[1] 糜茂俊[1] 徐圣言[1] 

机构地区：[1]江苏大学生物与环境工程学院,镇江212013

出　　处：《农业工程学报》2005年第6期148-151,共4页Transactions of the Chinese Society of Agricultural Engineering

基　　金：江苏省社会发展计划项目(BS2002024)

摘　　要：喷动床具有类似于稀相流化床的喷动区和类似于逆流密相移动床的环形区,结构简单,传热传质效果好,可以考虑将其应用到绿麦芽干燥过程,以取代现有的耗时长、传热传质不均匀的固定床干燥工艺。为此,设计和试验了绿麦芽喷动床干燥机,其柱体内径为180mm,高为700mm,锥体部分高为100mm,锥角为90°,气体入口管内径为25mm。在每次装料量为3kg绿麦芽,空气流量为100m3/h的条件下,研究了9种绿麦芽的喷动干燥工艺,并对干燥产品的质量进行了多指标的检测。结果表明,较好的麦芽喷动干燥工艺为:60℃热空气干燥4h后,85℃热空气加热麦芽使其升温至80℃,最后再使用85℃热空气焙焦2.5h。整个喷动干燥过程用时8h,与传统工艺18～20h相比,干燥时间明显缩短。能耗量约为5700kJ/kg水,相对于一般麦芽厂的能耗节约了大约30%。产品麦芽的含水率为4.74%(湿基),色度(欧洲啤酒协会)为4.25,浸出率为81%,α-氨基氮为157.6mg/(100g),粗细粉差为1.5%,糖化时间为9min,都达到优等浅色麦芽的指标。A spouted bed with spout region similar to a dilute phase fluidized bed and annulus region similar to a countercurrent closely moving bed has a simple structure and good effects of heat and mass transfer and may be used to dry green malt for replacing the present technology with packed bed in which heat and mass transfer is not even. Therefore, a spouted bed dryer was designed and tried with a column of 180 mm in inner diameter and 700 mm in height, a cone of 100 mm in height and 90° in conic angle, and a gas inlet of 25 mm inner diameter. Nine experiments of drying green malt were carried out with the spouted bed on conditions that 3 kg green malt was charged and air flow rate was 100 m3/h each time. The quality of malt was examined in terms of several indexes. The results indicated that a better drying technology was obtained when green malt was dried by 60°C hot air for 4 h at first, then heated to 80°C by 85°C hot air, and baked by 85°C hot air for 2.5 h at last stage. The processing time was obviously less than that of traditional technology. The energy consumption was about 5700 kJ/kg water that was decreased by about 30% compared with the values at many malt production factories. The moisture content of dried malt was 4.74% (wb), Europe brewage corporation (EBC) color degree 4.25, soaking rate 81%, α-N 157.6 mg/(100 g), the difference between coarse powder and fine powder 1.5, mashing time 9 min. They all reached the standards of first-rate light color malt.

关 键 词：喷动床 绿麦芽 干燥 

分 类 号：TS262.5[轻工技术与工程—发酵工程]