共查询到19条相似文献,搜索用时 235 毫秒
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基于Fluent的节能型干燥窑内部结构优化研究 总被引:1,自引:0,他引:1
为使设计的节能型干燥窑内部结构能够满足锯材干燥生产时具有较为均匀的流场分布和较大的风速,本研究利用Fluent软件,对不同配气道宽度和不同进排气道结构参数下的节能型干燥窑内速度场进行数值模拟分析。结果表明,节能型干燥窑内材堆中下两层气流分布较为均匀,材堆顶层气流低流速区域随进排气道高度和配气道宽度的增加而有所减少,材堆内部的高流速区域随进排气道高度和配气道宽度的增加而略有加大。从气流在材堆内部整体流速和均匀性的角度出发,结合生产实际,设计节能型干燥窑内部结构时以进排气道高度为1 000 mm,配气道宽度为1 000 mm为最佳。 相似文献
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刘宝祥 《林业机械与木工设备》1993,(4):79-82
室干过程中,测量木材的含水率是执行含水率基准和决定干燥终点的前提.木材易于产生弯曲,木材未干、板材含水率达不到标准若再次干燥,势必增加成本.监测干燥室内板材含水率有以下几种方法:用电阻和电容式水分仪测量;测量气流穿过材堆前后温度差,然后按经验公式推算含水率;用材堆的细 相似文献
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一、正确这择温度计位置的意义在木材干燥过程中,干燥室内空气介质的温湿度是按照制定好的干燥基准,通过湿度计所测得的干球温度和湿球温度来指示、调节和控制的。故湿度计在干燥室内的位置一定要真正反映,代表干燥室内空气介质的温湿度。而干燥室内不同位置(如材堆的进、出风口。材堆的顶部和底部、干燥室内沿长度方向靠近或远离大门等)其空气介质的温湿度均有较明显的差异,因之温湿度只能是一个平均数值。如该值测量失误,就会产生干燥基准控制的失灵,导致产生如下两种情 相似文献
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介绍了周期式短轴型木材干燥室的主要结构,分析了介质湿度调节系统在木材干燥设备工作中的重要作用,针对生产实际的效果,对湿度调节系统的设计进行了论述,并介绍了该系统的进排气道装置、增湿装置的结构设计、理论分析及设计计算方法与步骤。设计的木材干燥室设备,提高了木材干燥质量,达到了预期的效果。 相似文献
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基于热流耦合的木材干燥窑风速温度分布解算 总被引:1,自引:0,他引:1
为构建木材干燥窑内部循环风速和温度合理分布,采用二维数值模拟方法,利用Fluent软件对试验型小型干燥窑进行仿真模拟,对比安装导流板前后干燥窑内温度和分布情况。木材干燥窑的设计,风速、温度分布是关键问题。首先利用ICEM CFD软件对结构简化的试验型小型干燥窑进行参数化建模,将简化的模型进行网格划分,利用Fluent软件对木材干燥窑内的流动与传热耦合环境进行数值模拟,得出风速分布云图和温度分布云图,研究干燥窑内热流耦合系统,得出其内部速度和温度的具体状态,通过导流板安装前后数值对比,找到导流板合理性的参数。采用二维数值的模拟方法,不能代表实际干燥窑工作状况,具有一定的局限性。 相似文献
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高温热泵除湿木材干燥室研究设计 总被引:1,自引:0,他引:1
高温热泵除湿木材干燥室研究设计田赞成,高健民1新干燥室设计思路除湿式木材干燥室的除湿机功能是除去空气中的水蒸汽,向空气提供工艺需要的热量,调节空气状态,以按干燥基准操作。在除湿机和干燥室的工艺匹配设计中,除了除湿机制热量以外,在热量的衡算中,还需设计... 相似文献
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新型环保节能木材蒸煮干燥窑 总被引:1,自引:0,他引:1
介绍一种新型环保节能木材蒸煮干燥窑,其可以将木材染色、漂白和干燥一次完成,从而降低了劳动强度,减少了设备投资,缩短了生产周期,提高了生产效益.同时还可以实现自动控制,减少木材的干燥缺陷. 相似文献
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《Wood material science & engineering》2013,8(1-2):12-20
Abstract Progressive (semi-continuous) kilns for softwood drying are very common in Finland and Sweden and are used in some other countries too. A simulation program has been developed that covers all three types of this kiln. The program calculates the climate in the length direction of the kiln and moisture content, moisture profile, wood temperature, slicing test gap and stress development. Energy consumption and drying costs may also be determined. The temperature level is the most important parameter regarding kiln efficiency. Two-zone progressive kilns are found to be more efficient than single-zone kilns. Progressive kilns have lower energy consumption and drying costs than batch kilns. Experimental full-scale tests show that the timber quality from a progressive kiln is comparable to, or in some cases even better than, timber dried in batch kilns. 相似文献
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Kana Yamashita Yasuhiko Hirakawa Shuetsu Saito Hiroshi Nakatani Motoyoshi Ikeda Masamitsu Ohta 《Journal of Wood Science》2012,58(3):259-266
To investigate the factors affecting the surface-check variation in boxed-heart square timber of sugi (Cryptomeria japonica), surface checks formed by the conventional kiln drying were compared for two stem heights of five cultivars with different wood properties. The total length and average length of the surface checks were greater at the upper part of the stems for all the cultivars. This might be caused by more sapwood at the upper part of the stem, and large drying stresses between the outer sapwood and the inner heartwood. The cultivars, in which tangential shrinkage was large owing to small microfibril angle, formed longer surface checks and smaller bow. There was a positive relationship between surface-check length and tangential shrinkage. The heartwood percentage and tangential shrinkage were thought to be important factors affecting the surface-check variation in sugi boxed-heart square timber. 相似文献
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金属壳体木材干燥窑热损失分析 总被引:1,自引:0,他引:1
本文主要分析了金属壳体木材干燥窑窑体的热损失情况。并与砖混结构窑窑体的热损失进行了对比。着重说明由窑门及边框冷桥产生热损失的严重程度,并指出减小热损失的一些途径。 相似文献
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High temperature and chemical effects on wood stability 总被引:9,自引:0,他引:9
W. E. Hillis 《Wood Science and Technology》1984,18(4):281-293
Summary The increasing supplies of fast-grown woods grown on short roations contain significantly higher proportions of juvenile wood with properties different from those of mature wood. Improved processes will be required to produce dried wood that is satisfactorily stable with few distortional or dimensional changes. The basic wood features affecting different forms of instability are considered. Variations in the amounts of cellulose, hemicelluloses and lignins in wood, the changes in them and the degradation products formed under different conditions are discussed. Changes in the nature of hemicelluloses appear to play an important role in conveying stability. The different volumes of heartwood in green timber have an effect on moisture levels and other properties. As industry is increasing kiln temperatures for high-temperature drying, the effect of time-temperature-moisture relationships on stability and degradation are discussed. The effect of ammonia and other chemicals on stability is considered. 相似文献