“八角烘干工艺的创新开发与八角烘干设备的研制”达到国内同行业领先水平

由南宁市森特公司和广西林科院共同承担的“八角烘干工艺的创新开发与八角烘干设备的研制推广”项目 ,经过两年的工作 ,顺利地完成了《双向四时段十控八角烘干工艺》研究和 5ＨＸ— 1 2型网床屉式八角烘干机的试制。 5ＨＸ— 1 2型烘干机于 2 0 0 1年 11月通过广西农机鉴定站测试。该机型具有以下特点 :(1)实现—机内—序完成杀青、烘干降水 ,减少了工序 ,减轻劳动强度和提高烘干效率。 (2 )采用物料静止气流换向 ,使物料水分均匀 ,破碎少。 (3)采用控湿、控温、控降水速度、控色变时点 ,烘出的八角颜色为棕褐或褐红。 (4)经济性好 ,即设备…     

八角的加工、深加工与利用

八角的传统加工方法是直接晒干。近几年来对八角果实机械烘干还停留在技术开发阶段。八角作为调味料应用于烹饪及食品加工,作为药物用于神经衰弱,消化不良。八角含芳香油5％～8％,脂肪油约22％以及蛋白质、树脂等,通过深加工,可提取茴油及八角树脂油。     

快速提取分离八角茴香油的新方法

将回流提取法、水蒸气蒸馏法、快速提取法对八角枝叶或干果中八角茴香油提取进行了比较,并确定八角枝叶或干果中八角茴香油的最佳提取方法和条件。结果表明,快速提取法比回流提取法、水蒸气蒸馏法提取效率高,快速简便。快速提取法提取八角茴香油的最佳条件为:干果原料与水比为1∶6,提取回流时间为2 h,产品收率达12.78%,且含八角茴香脑90.83%。     

广西优势经济林八角深加工将于九月投产

八角在食品、医药、化妆品等工业加工方面应用广泛:干果气味芳香,有“味王”之美誉,在烹调、腌菜、五香炒货上应用广泛;中国出口的四种香味有两种来自八角;直接入药,有补热、驱虫、促乳、止咳等功效;近年专家们发现,从八角中提取的莽草酸可治疗畜流感。广西是八角原产地和主产区,有“世界八角之乡”的美称。全区现有八角林面积35.04万公顷,最高年产量达8万多吨干果,栽培面积和产量均占全国的85%以上。然而广西的八角一直以出售干果为主,缺少深加工。广西万山香料有限责任公司填补了这一空白。该公司位于灵山县工业集中区,占地43000平方米,目…     

不同处理方式对八角莽草酸和茴香油含量的影响

为研究不同处理方式对八角莽草酸和茴香油含量的影响,以广西壮族自治区国有六万林场的八角果为原料,莽草酸和茴香油含量为指标,采用水蒸气蒸馏法提取莽草酸和茴香油,高效液相色谱法（HPLC）检测莽草酸含量,气相色谱法检测茴香油中主要成分含量。研究结果表明,不同处理方式对莽草酸和茴香油含量影响不同。莽草酸含量最高的处理方式是100℃开水杀青后晒干,为9.64%;含量最低的处理方式是微波杀青后烘干,为7.35%。茴香油含量最高的处理方式是薄膜包住杀青后晒干,为4.23%;含量最低的处理方式是100℃开水杀青后烘干,为3.12%。不同方式处理八角所提取茴香油中茴脑含量均在90%以上。     

马锦林:八角抱团闯市场

近年的八角市场不景气。八角干果价格从2000年的每公斤30元,呈直线下降,直到2012年的每公斤6-10元。2012年鲜八角的收购价为每公斤2.6元,除去人工费每公斤1.6元以及管护等费用,林农种植八角的利润已接近于零。八角长期低迷的价格,让大多数种植     

十一个角的八角

最近笔者在藤县八角主产地古龙镇古龙村了解到，该镇交通管理站站长祝海家责任山上有一株挂十一个角果实的八角果树，于是专程到这株树下了解、拍照。祝海说，这片八角林是孤年代分责任山时领到的，那时就发现整片八角林只有这株长的果都是十一个角，每年生果产量都保持在50至300斤（一般八角树产果50公斤左右），出售干果时老板都愿加价0．5元收购。现在有人愿出4元一株买他这株八角的苗，而普通八角亩只能卖0．5至0．6元一株。据推测，这株树的直径有33厘米左右，高约十五六米，生果比一般的八角生果大。笔者认为值得培育推广。十一个角的…     

八角适收期的确定

八角每年开花两次:第一次在2～3月间,8～9月果熟,其产量占全年产量的90％以上,叫“大红果”。第二次在8～9月间,次年3～4月间果熟,产量较少,叫“四季果”。 为了掌握八角最适合的采收时间,1992年我们做了一项对比试验:在同一株八角树,分别于7月、8月、9月采收,结果7月采收生果2.5～2.7公斤,经过加工、晒干得到0.5公斤干果;8月采收生果2～2.3公斤,经过     

林下营造八角优点多

八角是一种重要的经济树种。八角成林纯收入约为投资成本的10倍。大力发展八角生产是山区群众脱贫致富的途径。大明山是八角适宜栽培区，由于该山体的八角高产区均集中分布在500－1000米的海拔高度内，地形坡度大，且以具有软强蓄水功能的阔叶林分布为多，营造八角如采取全面清理、全垦整地的方式则容易引起水土流失，所以，该区域八角的造林方式大多以林下营造为主。实践证明，此方法不但避免了水土流失，而且还具有采伐迹地种植方式所不及的优点。1．苗木恢复快、根系伸展快。林下营造八角，避免了苗木水分的大量蒸发。因而，八角定植后约…     

两种八角叶挥发油含量和化学成分的季节变化

采用水蒸气蒸馏法提取不同季节软枝八角和硬枝八角新鲜枝叶中的挥发油,用GC-MS对挥发油的成分进行分析。考察了两种八角枝叶挥发油含量和化学成分随季节变化的规律,以挥发油的提油率为指标,确定八角叶最佳的采收季节。结果表明,硬枝八角叶的挥发油含量大于软枝八角叶的;秋季(9—11月)和冬季(12—2月)两种八角叶挥发油的含量高于春季(3—5月)和夏季(6—8月),并且在秋季为挥发油含量较高的季节,软枝八角叶和硬枝八角叶含量最高分别达到了0.83%和0.84%,是八角叶采摘最佳的季节。不同季节挥发油化学成分基本一致,但各组分含量存在一定的差异。挥发油主要成分是反式茴香脑、草蒿脑、对甲基苯甲醛、桉叶油醇、芳樟醇、1-(3-甲基-2-丁烯基)-4-(1-丙烯基)苯等。挥发油中代表成分反式茴香脑在秋季含量最高,草蒿脑含量在春季最高。     

刨花干燥工序关键含水率的确定

刨花的干燥质量主要依据最终干燥含水率的偏差，均匀性以及干刨花的破损程度来衡量，本文着重阐述了刨花干燥过程中直接决定这些干燥质量因素的关键含水率，以及它们的作用和确定的依据。     

铅笔板高温热压改性技术研究

为克服高温烤板处理的缺点 ,进行了椴木铅笔板热压干燥基本规律及温度、时间与含水率的关系研究和热压干燥的铅笔板与烤板的吸湿性、脆性对比试验。研究结果表明 :高温热压可使木材进行热分解 ,热压干燥后的铅笔板的吸湿性和脆性能达到烤板的要求 ,并在质量稳定性方面优于烤板 ,更重要的是它解决了烤板对环境的污染问题     

采后处理方式对五倍子品质的影响

对比了蒸汽烫漂(SB)和沸水浸烫(BWB)2种预处理方式对新鲜五倍子的影响,以及经过预处理后分别采用烘箱干燥(OD)、流化床干燥(FBD)、自然干燥(ND)和紫外光辐照(UVI)4种干燥方式所得五倍子产品的品质。对干燥速率及产品指标的分析结果表明:预处理后五倍子含水率和单宁酸含量均有所降低,尤其是蒸汽烫漂后,含水率降为47.68%,与未处理五倍子含水率(55.77%)呈显著性差异;加热处理会使五倍子干燥产品中单宁酸的含量降低而没食子酸的含量增加,自然干燥的五倍子单宁酸质量分数在50.12%~56.84%之间,没食子酸质量分数在0.29%~0.46%之间,而烘箱干燥后五倍子中单宁酸质量分数仅为32.48%~42.43%,没食子酸质量分数高达2.97%~4.39%;不同采后处理方式对产品品质有不同的影响,沸水浸烫或蒸汽烫漂与紫外光辐照相结合可提高五倍子的干燥速率,且对产品单宁酸含量影响较小;烘箱和流化床干燥可将干燥时间降为5 h以内,但所得五倍子产品中单宁酸质量分数显著降低,均在32%~43%之间;沸水浸烫或蒸汽烫漂后自然干燥能保证单宁酸的结构最接近原始状态,但干燥时间高达200 h以上;所以可根据实际的操作条件和后续的应用选择五倍子的采后处理方式。工业化五倍子的采后处理因更注重干燥效率,以蒸汽烫漂预处理辅之以流化床干燥方式为佳。     

意杨薄板材干燥工艺研究

应用高温干燥与常温干燥有机结合的工艺技术(简称蒸汽综合干燥法),对意杨25mm厚板材进行处理,在预热阶段进行充分的汽蒸处理,而后进入常压过热蒸汽干燥工艺阶段,当含水率降到25%时,转入常温干燥工艺阶段,直到干燥阶段结束。这样既缩短了干燥周期又提高了干燥质量,同时也提高了干燥窑的生产效率。     

Climate control in vacuum dryers for convective heat transfer

The European Drying Group (EDG) proposal on a wood drying quality standard defines demands on final moisture content variation of the dried wood. The final moisture content variation will depend on material parameters as well as the production process and the wood will always show a “natural” moisture content variation after drying. Thus the drying process has to be defined well enough to allow for the natural moisture content variation in order to fulfil the demands of the drying standards. As the average equilibrium moisture content of the wood in a vacuum drying kiln with pure steam atmosphere is determined by the pressure and the temperature, the demands on the climate control system to fulfil the demands of the drying standard can be calculated with regard to the natural moisture content variation of the wood. In the first part of this contribution the demands on climate control in vacuum dryers are calculated based on the EDG-standard and the natural moisture content variation. In the second part of the contribution the demands on climate control are compared with climate and moisture content measurements from industrial production in vacuum kilns. Critical factors in kiln design and climate control system design necessary to maintain a controlled drying climate are listed.     

金檀干燥工艺的研究

文章采用百度试验法对金檀木材进行干燥特性研究,提出金檀家具用料板材的干燥基准,并进行了工艺试验研究。结果表明,金檀木材初期开裂为5级;内裂为2级;截面变形为3级,干燥速度为4级。初期开裂较严重,干燥速度慢,故金檀为难干燥木材。采用给出的干燥工艺,42 mm厚铁线子地板坯料从初含水率30.66%干燥到12.8%的干燥周期为43d,干燥质量满足家具用料的加工要求。     

小型除湿干燥机干燥乐器用材的实践

本研究使用小型除湿干燥机对提琴用材进行了干燥工艺生产性试验。结果表明，干燥过程中试材未产生内裂和表裂；干燥后板材的含水率在材堆内分布均匀，在板材厚度方向分布有一定差异，平衡后可以使用；干燥成本在100元/m^3左右；干燥后的木材质量符合乐器制作的要求。本试验确定的干燥工艺可适用楔形不规则乐器用材，还可进行不同规格乐器用材的混合干燥。     

Effects of basic density,annual growth and drying schedule on selected quality factors of dried Siberian larch (Larix sibirica) timber

Abstract

Siberian larch (Larix sibirica Ledeb.) timber is suitable for many uses in the mechanical wood industry. Drying it without any decrease in value, however, is difficult and slow. The purpose of this research was to compare the drying quality of Siberian larch timber dried with three different conventional schedules taking into account the density and annual growth of wood. Five drying tests were performed. The final moisture content (MC), MC gradient, cracks, deformations (bow, crook, twist and cup) and case hardening were measured from the dried timber. The basic density particularly affected the MC, as shown in the differences regarding dried wood, with the denser wood having higher final MC and MC gradient. It was also found that large annual growth increased some deformations. Most of the measured factors were best after drying at the highest temperatures used; however, a slightly different trend was observed for bow, twist and cup. MC factors and twisting were the most problematic properties in drying according to this study. Sorting Siberian larch timber, particularly according to density, would improve the MC properties of dried timber by ensuring sufficient drying time, as economically as possible, for each timber piece.     

A global rheological model of wood cantilever as applied to wood drying

In the process of wood drying inevitable stresses are induced. This often leads to checking and undesired deformations that may greatly affect the quality of the dried product. The purpose of this study was to propose a new rheological model representation capable to predict the evolution of stresses and deformations in wood cantilever as applied to wood drying. The rheological model considers wood shrinkage, instantaneous stress–strain relationships, time induced creep, and mechano-sorptive creep. The constitutive law is based on an elasto–viscoplastic model that takes into account the moisture content gradient in wood, the effect of external load, and a threshold viscoplastic (permanent) strain which is dependent on stress level and time. The model was implemented into a numerical program that computes stresses and strains of wood cantilever under constant load for various moisture content conditions. The results indicate that linear and nonlinear creep behavior of wood cantilever under various load levels can be simulated using only one Kelvin element model in combination with a threshold-type viscoplastic element. The proposed rheological model was first developed for the identification of model parameters from cantilever creep tests, but it can be easily used to simulate drying stresses of a piece of wood subjected to no external load. It can therefore predict the stress reversal phenomenon, residual stresses and maximum stress through thickness during a typical drying process.     

A study on contact drying with flexible screen

hibobctionHOt press drying is referred to dry veneers betweenplat6ns. H6St is thensPOrt6d from plat6n to veneercontinuousty (Sandoe 1983). Many experiments haveshown that hot press may reduce drying time andIncreaSe h6at nescient. In addition, hot press driedveneer is flat and smOOth, which is desirable to glue,~bly as well as curtsin coat (Lu 1993). Compered We conventional air circulating drieF, hot pressdrier 1. simpler in struCture, cheaper in price andmore economical in operation (L…