冻融-热泵干燥机的设计与试验优化
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摘要
为探究冻融处理对香菇热泵干燥特性的影响,设计了一种冻融-热泵干燥机。依据自制冻融-热泵干燥机的结构特点,在干燥箱内的5个不同位置布置9个干燥床架,并在每个床架上均匀布置若干料盘。根据冷冻与融化速率对香菇物理性质的影响,设计快冻慢融的冻融干燥方法。重点考察新鲜香菇干燥品质的变化情况,主要指标有干基含水率、水分比、复水性、色差、干燥速率、有效水分扩散系数等,并结合4种典型薄层干燥模型,利用水分比进行数据拟合,从而建立干燥数学模型。结果表明:冻融香菇在干燥箱不同位置有效水分扩散系数在1.98×10-7～2.36×10-7m2/s之间,色差、复水性差异性小,干燥后感官性较好,且复水值总体与色差L值呈正比;香菇冻融干燥各位置水分比和干燥速率变化情况基本一致,均匀性好。经过4次冻融处理,每次冻融后干燥速率短时间内有一定提高,随后下降,且随着冻融次数的增加,其对水分迁移速率的影响呈下降趋势,第4次冻融后干燥速率无明显变化,说明随着香菇含水率的下降,冻融处理对水分的剥离能力逐渐减弱。在20 h进入单纯热泵干燥阶段,在30 h基本达到平衡含水率,单纯热泵干燥过程存在加速与降速阶段,无明显恒速干燥阶段。冻融香菇在不同干燥条件下的干燥过程均满足Henderson and Pabis方程,其中待定系数a,b,c,k,g,h与层架之间呈5次方关系,相关系数R2为0.998。本文为冻融-热泵干燥机的设计及香菇冻融干燥提供参考。
In order to explore the influence of freezing and thawing to the character of mushroom heat pump drying,designed a kind of freezing and thawing dryer.According to the structural features of freezing and thawing dryer,in five different positions of the drying box arrange nine drying bed,and in each frame are uniformly arrang some trays.In line with influence of the speed of frozen and thaw to physical property of mushroom,designed experiment scheme which fast frozen and slow melt.The experiment focused on the change of fresh letinous drying quality,leading indicator contain dry base moisture content,water ratio,rehydration,color difference,drying rate,effective moisture diffusion coefficient etc.and combine with four classic lamina dry model,taking advantage of water ratio to fit data,and establish dry mathematic model.The experimental results show that:the effective moisture diffusion coefficient of freeze-thaw of Letinous edodes in the drying box at different position is between 1.98 ×10-7 m2/s and 2.36×10-7 m2/s,color,rehydration of small differences,good sense of drying,and the rehydration value is proportional to L value.The change of moisture ratio and drying rate of Letinous edodes at different positions is consistent.After four times freeze-thaw treatment,each freeze-thaw after drying rate in short time has increased,then decreased.With the increase of freezing thawing times,the capacity of peel water is decline,increasing rate after the fourth freeze-thaw has no obvious change,manifestin the capacity of drive water migration has negative correlation with water content for Letinous edodes.At the time of twentieth,reaching pute heat pump drying stage,and the equilibrium moisture content is reached at the beginning of the 30 th hour.There is a stage of acceleration and deceleration in the heat pump drying process,but don't exist obvious constant rate drying stage.The drying process of Letinous edodes under different drying conditions can be satisfied with the Henderson and Papis equation,and the undetermined coefficients a,b,c,k,g,h and the layer are 5 square relationship,the correlation coefficient R2 is 0.998.This paper provides a reference for the design of freeze thaw heat pump dryer and freeze thaw drying of Letinous edodes.
In order to explore the influence of freezing and thawing to the character of mushroom heat pump drying,designed a kind of freezing and thawing dryer.According to the structural features of freezing and thawing dryer,in five different positions of the drying box arrange nine drying bed,and in each frame are uniformly arrang some trays.In line with influence of the speed of frozen and thaw to physical property of mushroom,designed experiment scheme which fast frozen and slow melt.The experiment focused on the change of fresh letinous drying quality,leading indicator contain dry base moisture content,water ratio,rehydration,color difference,drying rate,effective moisture diffusion coefficient etc.and combine with four classic lamina dry model,taking advantage of water ratio to fit data,and establish dry mathematic model.The experimental results show that:the effective moisture diffusion coefficient of freeze-thaw of Letinous edodes in the drying box at different position is between 1.98 ×10-7 m2/s and 2.36×10-7 m2/s,color,rehydration of small differences,good sense of drying,and the rehydration value is proportional to L value.The change of moisture ratio and drying rate of Letinous edodes at different positions is consistent.After four times freeze-thaw treatment,each freeze-thaw after drying rate in short time has increased,then decreased.With the increase of freezing thawing times,the capacity of peel water is decline,increasing rate after the fourth freeze-thaw has no obvious change,manifestin the capacity of drive water migration has negative correlation with water content for Letinous edodes.At the time of twentieth,reaching pute heat pump drying stage,and the equilibrium moisture content is reached at the beginning of the 30 th hour.There is a stage of acceleration and deceleration in the heat pump drying process,but don't exist obvious constant rate drying stage.The drying process of Letinous edodes under different drying conditions can be satisfied with the Henderson and Papis equation,and the undetermined coefficients a,b,c,k,g,h and the layer are 5 square relationship,the correlation coefficient R2 is 0.998.This paper provides a reference for the design of freeze thaw heat pump dryer and freeze thaw drying of Letinous edodes.
引文
[1]李顺峰,王安建,侯传伟,等.废弃双孢蘑菇菇柄微波真空干燥特性及动力学模型[J].中国食品学报,2016,16(2):181-188.
[2]郭树国,蒋爱国,王丽艳.基于品质和能耗的猕猴桃真空冷冻干燥工艺优化[J].食品研究与开发,2016,37(4):108-112.
[3]陈健凯,林河通,李辉,等.杏鲍菇热风-微波真空联合干燥工艺参数优化[J].中国食品学报,2014,14(9):131-140.
[4]刘业凤,周国梁,李续.真空冷冻干燥蒜丁实际生产的能耗研究[J].农业工程学报,2014,30(10):242-247.
[5]CLAUSSEN I C,ANDRESEN T,EIKEVIK T M,et al.Atmospheric freeze drying-modeling and simu lation of a tunnel dryer[J].Drying Technology,2007,25(12):1959-1965.
[6]毕金峰,陈瑞娟,陈芹芹,等.不同干燥方式对胡萝卜微粉品质的影响[J].中国食品学报,2015,15(1):136-141.
[7]张容鹄,高元能,冯建成,等.热泵干燥槟榔中试工艺参数优化[J].农业工程学报,2016,32(9):241-247.
[8]高鹤,易建勇,毕金峰,等.番木瓜真空冷冻联合变温压差膨化干燥工艺优化[J].中国食品学报,2016,16(7):156-163.
[9]马渊,彭晓峰.单向冷冻过程溶液中冰晶界面的竞争现象[J].化工学报,2008,59(11):2857-2863.
[10]马渊.生物材料冷冻特性及冻融传递现象机理[D]北京:清华大学,2008.
[11]李敏,吴宝川,关志强,等.适宜添加剂预处理提高罗非鱼片冻融-热泵干燥品质[J].农业工程学报,2014,30(17):295-304.
[12]郭婷,何新益,邓放明,等.冻融处理对甘薯风干燥产品品质影响[J].天津农学院学报,2013,20(3):9-13.
[13]郭婷,何新益,邓放明.冻融甘薯热风干燥特性与动力学研究[J].食品与机械,2013,29(3):8-11.
[14]郭婷,何新益,邓放明,等.利用LF-NMR探讨冻融处理影响甘薯膨化产品品质的机理[J].农业工程学报,2013,29(17):279-285.
[15]何新益,郭婷,邓放明,等.冻融处理对甘薯变温压差膨化干燥动力学的影响[J].中国粮油学报,2016,31(5):32-37.
[16]潘永康,王喜忠,刘相东.现代干燥技术第2版[M]北京:化学工业出版社,2007:466-468.
[17]崔春芳,童忠良.干燥新技术及应用[M].北京:化学工业出版社,2009:305-312.
[18]段智英,郭玉明,王福贵.基于格子Boltzmann方法分析果蔬真空冷冻干燥冻干速率[J].农业工程学报,2016,32(14):258-264.
[19]曾目成,毕金峰,陈芹芹,等.渗透-中短波红外联合干燥对猕猴桃切片干燥特性及动力学模型的影响[J].中国食品学报,2014,14(10):83-91.
[20]关志强,王秀芝,李敏,等.荔枝果肉热风干燥薄层模型[J].农业机械学报,2012,43(2):151-158.
[21]陈健凯,林河通,李辉,等.杏鲍菇微波真空薄层干燥数学模型建立与评价[J].真空科学与技术学报,2013,33(12):1184-1190.
[22]沈琪,李顺峰,王安建,等.双孢菇废弃物菇柄热风干燥特性及动力学模型[J].中国食品学报,2015,15(1):129-135.
[23]赵珂,肖旭霖.核桃气体射流冲击干燥特性及干燥模型[J].中国农业科学,2015,48(13):2612-2621.
[24]TSYTSARAU M,PALPANAS T,CASTELLANOS MDynamics of news events and social media reaction[J].2014,90(1/2):901-910.
[25]郑海波,江美都,傅玉颖,等.低温低湿条件下海鳗冷风干燥动力学特性[J].中国食品学报,2012,12(2):73-80.
[26]徐凤英,黄木水,陈震,等.稻谷烘干过程中的水分扩散特性与品质特性[J].农业工程学报,2016,32(15):261-267.
[27]WANG Z,SUN J,CHEN F,et al.Mathematical modeling on thin layer microwave drying of apple pomace with and without hot-air pre drying[J].Journal of Food Engineering,2007,80(2):536-544.
[28]应巧玲,励建荣,傅玉颖,等.食品薄层干燥技术的研究进展[J].中国粮油学报,2010,25(5):115-119.
[29]陈良元,韩李锋,李旭,等.茄子片热风干燥收缩特性及其修正的湿分扩散动力学模型[J].农业工程学报,2016,32(15):275-281.
[30]杨爱金,毕金峰,刘璇,等.预干燥含水率对苹果片变温压差膨化干燥特性的影响[J].中国食品学报,2014,14(2):180-186.
[2]郭树国,蒋爱国,王丽艳.基于品质和能耗的猕猴桃真空冷冻干燥工艺优化[J].食品研究与开发,2016,37(4):108-112.
[3]陈健凯,林河通,李辉,等.杏鲍菇热风-微波真空联合干燥工艺参数优化[J].中国食品学报,2014,14(9):131-140.
[4]刘业凤,周国梁,李续.真空冷冻干燥蒜丁实际生产的能耗研究[J].农业工程学报,2014,30(10):242-247.
[5]CLAUSSEN I C,ANDRESEN T,EIKEVIK T M,et al.Atmospheric freeze drying-modeling and simu lation of a tunnel dryer[J].Drying Technology,2007,25(12):1959-1965.
[6]毕金峰,陈瑞娟,陈芹芹,等.不同干燥方式对胡萝卜微粉品质的影响[J].中国食品学报,2015,15(1):136-141.
[7]张容鹄,高元能,冯建成,等.热泵干燥槟榔中试工艺参数优化[J].农业工程学报,2016,32(9):241-247.
[8]高鹤,易建勇,毕金峰,等.番木瓜真空冷冻联合变温压差膨化干燥工艺优化[J].中国食品学报,2016,16(7):156-163.
[9]马渊,彭晓峰.单向冷冻过程溶液中冰晶界面的竞争现象[J].化工学报,2008,59(11):2857-2863.
[10]马渊.生物材料冷冻特性及冻融传递现象机理[D]北京:清华大学,2008.
[11]李敏,吴宝川,关志强,等.适宜添加剂预处理提高罗非鱼片冻融-热泵干燥品质[J].农业工程学报,2014,30(17):295-304.
[12]郭婷,何新益,邓放明,等.冻融处理对甘薯风干燥产品品质影响[J].天津农学院学报,2013,20(3):9-13.
[13]郭婷,何新益,邓放明.冻融甘薯热风干燥特性与动力学研究[J].食品与机械,2013,29(3):8-11.
[14]郭婷,何新益,邓放明,等.利用LF-NMR探讨冻融处理影响甘薯膨化产品品质的机理[J].农业工程学报,2013,29(17):279-285.
[15]何新益,郭婷,邓放明,等.冻融处理对甘薯变温压差膨化干燥动力学的影响[J].中国粮油学报,2016,31(5):32-37.
[16]潘永康,王喜忠,刘相东.现代干燥技术第2版[M]北京:化学工业出版社,2007:466-468.
[17]崔春芳,童忠良.干燥新技术及应用[M].北京:化学工业出版社,2009:305-312.
[18]段智英,郭玉明,王福贵.基于格子Boltzmann方法分析果蔬真空冷冻干燥冻干速率[J].农业工程学报,2016,32(14):258-264.
[19]曾目成,毕金峰,陈芹芹,等.渗透-中短波红外联合干燥对猕猴桃切片干燥特性及动力学模型的影响[J].中国食品学报,2014,14(10):83-91.
[20]关志强,王秀芝,李敏,等.荔枝果肉热风干燥薄层模型[J].农业机械学报,2012,43(2):151-158.
[21]陈健凯,林河通,李辉,等.杏鲍菇微波真空薄层干燥数学模型建立与评价[J].真空科学与技术学报,2013,33(12):1184-1190.
[22]沈琪,李顺峰,王安建,等.双孢菇废弃物菇柄热风干燥特性及动力学模型[J].中国食品学报,2015,15(1):129-135.
[23]赵珂,肖旭霖.核桃气体射流冲击干燥特性及干燥模型[J].中国农业科学,2015,48(13):2612-2621.
[24]TSYTSARAU M,PALPANAS T,CASTELLANOS MDynamics of news events and social media reaction[J].2014,90(1/2):901-910.
[25]郑海波,江美都,傅玉颖,等.低温低湿条件下海鳗冷风干燥动力学特性[J].中国食品学报,2012,12(2):73-80.
[26]徐凤英,黄木水,陈震,等.稻谷烘干过程中的水分扩散特性与品质特性[J].农业工程学报,2016,32(15):261-267.
[27]WANG Z,SUN J,CHEN F,et al.Mathematical modeling on thin layer microwave drying of apple pomace with and without hot-air pre drying[J].Journal of Food Engineering,2007,80(2):536-544.
[28]应巧玲,励建荣,傅玉颖,等.食品薄层干燥技术的研究进展[J].中国粮油学报,2010,25(5):115-119.
[29]陈良元,韩李锋,李旭,等.茄子片热风干燥收缩特性及其修正的湿分扩散动力学模型[J].农业工程学报,2016,32(15):275-281.
[30]杨爱金,毕金峰,刘璇,等.预干燥含水率对苹果片变温压差膨化干燥特性的影响[J].中国食品学报,2014,14(2):180-186.