麻赛尔横编织物的开发及其性能分析

为了更好地了解麻赛尔纤维针织物的服用性能,探讨了平针、1+1罗纹、双罗纹组织麻赛尔纤维针织物和棉纤维针织物的基本力学性能,并进行了对比分析。结果表明:在3种不同组织的麻赛尔针织物试样中,耐磨性:平纹最好,双罗纹次之,罗纹最差;透气性:平纹、罗纹、双罗纹依次降低。同样3种不同组织的棉纤维针织物也表现出同样的规律。在相同组织不同纱线试样中,麻赛尔针织物的耐磨性、透气性、抗起毛起球性均优于棉纤维针织物。     

Optimization and performance evaluation of silk fabrics dried in the domestic dryer

To determine the optimal drying procedure for large load and non-ironing procedure for small load when silk fabrics were drying-cared in daily usage; change in appearance, mechanical properties and microstructure of silk fabrics before and after drying with various drying parameters (heater power, air velocity and drum-rotating speed) were investigated. Results revealed that the performance of silk fabric after drying is more sensitive to air velocity (humidity of drying-air) rather than heater power (temperature). Heater power of 3000W, air velocity of 8.5m/s and drum rotating speed of 45-50rpm (No.2) was proved to be optimal for drying silk fabrics due to its ideal smoothness appearance, dimensional stability and drying efficiency. When consumers dry a small amount of clothes, a drying procedure of heater power of 3000W, air velocity of 8.5m/s and drum-rotating speed of 0rpm (No.6) is more reasonable procedure because it reduces or eliminates ironing. And indicating drying in dryer can be an effective alternative to indoor-drying or sunlight-drying if suitable procedure being set. This finding provided reference for manufacturers to design and improve of dryers, especially for drying procedures optimization of delicate textiles, and consumers a feasible care method without reducing the quality of fabric.     

三系统电脑横机三角底板及驱动滑板的设计

通过对现有双系统电脑横机主关零部件技术的分析,自主设计开发了新型三系统电脑横机编织结构,包括对三角底板、提花三角底板、滑板的设计;以及各部位零件的材料选择、加工工艺、零件装配、调试及批量生产等。该新型三角底板及三角驱动滑板符合设计要求,能与电脑横机其他机构配合运动,对本行业的技术改造可提供一些创新思路。     

碳化钙在食用农产品中的应用及其安全问题

碳化钙,俗称电石,作为水果催熟剂和植物调节剂被广泛用于农业。虽然随着碳化钙安全性问题的出现,其作为水果催熟剂的应用已被很多国家禁止,但有很多地区仍在使用。另一方面,近年来有大量文献报道碳化钙作为植物调节剂对植物生长的影响作用。本文综述了碳化钙的理化性质、在食用农产品中的应用以及碳化钙在应用中可能造成的安全性问题,补充碳化钙在安全性评价方面的文献缺失,为其进一步应用发展提供理论基础。      

新型微波真空干燥机设计

设计了一种集微波干燥与真空干燥于一体的新型装置,将波导和波源冷却装置融为一体,有效地解决了微波分布不均和微波源受热易损坏两大难题。物料室是微波室和真空室的交集,可以使物料既能受到微波辐射,又能处于真空环境中。分层设计的物料盘一方面可以方便拆卸,另一方面可以充分地利用物料室的空间。模块化的冷阱设计,使冷阱可以根据干燥的需求自由的装卸,可以有效地提高冷阱的利用效率。该微波真空干燥设备设计巧妙,安全可靠,可以满足高品质物料的干燥加工。     

澳洲坚果中红外干燥机设计与试验

针对澳洲坚果干燥时间长、能耗大等问题,设计了中红外干燥机,分析澳洲坚果干燥水分与速率变化规律,探明干燥水分扩散与活化能变化机制,运用1Stopt软件对典型干燥模型进行数据拟合并建立中红外干燥模型。结果表明,采用加热腔内60℃,中红外发射管0.8kW的干燥条件,经过360min果仁含水量降至1.36%的安全水分,整个干燥阶段主要为降速干燥,Midilli-Kucuk模型可以有效预测澳洲坚果在中红外干燥过程中水分的变化机制,各时段澳洲坚果的有效水分扩散系数在2.03×10-7～2.31×10-7 m2/s,利用阿伦尼乌斯公式计算出澳洲坚果的干燥活化能为159.5kJ/mol。     

Effectiveness of the solar biomass hybrid dryer for drying and disinfestation of maize

The Solar Biomass Hybrid Dryer (SBHD) is a new technology developed in Ghana for grain drying and utilizes biomass (agro-residues, timber scraps, etc.) along with solar drying, and is especially useful for drying during rainy periods of the year when solar drying cannot be relied on. This study assessed the effectiveness of a 5.0-MT SBHD comprising a solar tent and a furnace for thermal drying and disinfestation of maize. Mortalities of adults of Sitophilus zeamais (Motschulsky), Tribolium castaneum (Herbst) and Cryptolestes ferrugineus Stephens were assessed. Additionally, mortalities of immatures of these three species were assessed. Internal and cage temperatures (°C) in the SBHD, sun drying (SD) and laboratory (control) were monitored, as were moisture content (MC) and thermally (stress) damaged kernels (TDK) (%). During the 7-h experiment, mean internal temperatures in the SBHD, SD and laboratory were 52.3 ± 1.0 °C, 41.4 ± 0.8 °C and 30.3 ± 0.2 °C, respectively. Similarly, temperatures in cages in the SBHD (49.5 ± 1.0 °C) were higher than those for cages in the laboratory (29.9 ± 0.2 °C) and SD (38.2 ± 0.6 °C). Reduction in the moisture content of maize dried using SBHD, SD and under laboratory conditions were 7.7, 5.2 and 2.9%, respectively. This corresponded to grain MC reduction rates of 1.1%, 0.74% and 0.4% per hour. There was 100% mortality of S. zeamais and C. ferrugineus adults achieved in only the SBHD; some immatures of all three species survived in all three treatments. However, survival of immatures was highest in the laboratory, followed by SD and lowest in the SBHD for all three species. Percent TDK was higher in the SBHD (6.7 ± 0.9) than SD (3.3 ± 0.3) and laboratory (2.7 ± 0.3). These data show that the SBHD is effective for both drying and disinfestation of grain.     

无核紫葡萄太阳能干燥技术的研究

采用一种空气集热器-温室型太阳能干燥装置,在新疆石河子市的气候条件下验证了无核紫葡萄太阳能干燥的可行性,从2007年8月到10月间,进行了一系列的试验.试验表明:与自然晾晒相比,太阳能干燥周期缩短为原来1/3的时间,干燥质量也有大幅度的提高.     

辊模拉拔扁丝后张力系统的设计及对产品性能的影响

辊模拉拔设备在无后张力情况下,生产的扁丝减面率变化大,直线性不稳定,成品扁丝表面质量不好,对辊模、机架、特别是轴承的损伤比较大.针对上述问题,设计过线轮直径为200mm的后张力系统,并对原设备进行改进.试验结果表明,后张力对被加工材料的减面率有明显影响,在高度减小率相近的情况下,张力越大,扁丝减面率也越大;在相同后张力...     

Mathematical modeling and performance analysis of thin layer drying of bitter gourd in sensible storage based indirect solar dryer

An indirect forced convection solar dryer integrated with porous sensible heat storage medium was developed. The effect of porous thermal storage and mass flow rate of air on the performance of the system for drying bitter gourd was studied. The experimental setup consists of a blower, solar flat plate collector with corrugated absorber plate (2 m²) and a drying chamber. The thermal storage medium (pebble) is placed below the corrugated absorber plate, in the air passage as a porous medium. The experiments have been carried out with various mass flow rates of air and different drying models have been used for explaining the drying behaviour of sliced bitter gourd. The result shows that, (i) the initial moisture content 92% (w.b) of bitter gourd was reduced to 9% (w.b) in 7 h in the proposed drying system, while it was 10 h for open sun drying, (ii) the maximum specific moisture extraction rate was observed as 0.215 kg/kWh at the mass flow rate of 0.0636 kg/s and the corresponding specific energy consumption was 4.44 kWh/kg, (iii) the collector and drying efficiency of the system were 22% and 19% respectively. The two term model and Midilli–Kucuk model are most suitable for indirect solar dryer and open sun drying in terms of statistical parameter respectively. The drying inside sensible heat storage based indirect dryer was more consistent and produced better quality product as compared to open sun drying.Industrial relevance

• •Every year post harvest losses are increasing rapidly due to the lack of storage facilities.
• •Solar dryers are the most suitable technology that can be easily availed at low cost and in small scale and it can be used as an income generation option for farmers and women in rural areas.
• •The role of solar dryers in food processing industries is significant especially in developing countries in the following areas
  • oFor preserving fruits and vegetables
  • oDairy industries
  • oAgricultural crop drying
  • oTimber drying
  • oIndustrial waste drying
• •The utilization of thermal storage medium in the solar dryers is being focused much for the reasons of extending the availability of the system for operation and to achieve better quality of the products.

     

粮食烘干机温度控制系统的设计

设计一套粮食烘干机温度控制系统,以粮食烘干机水分测量系统为前置,用于谷物类粮食烘干过程中的变温控制.温度控制核心为STM32F103C8T6单片机,依靠步进电机驱动单元对可控硅调压器完成功率控制.绘制出PCB(Printed Circuit Board)板的布局布线,完成控制系统制作并进行联调测试.基于粮食烘干机水分测...     

Quality of cocoa beans dried using a direct solar dryer at different loadings

In this study fermented cocoa beans were dried in a direct solar dryer at three levels of loading (20, 30 and 60 kg). Surface mouldiness was found to be heavy in the 60 kg treatment, with beans appearing blackish. All the dried beans were reasonably acceptable in terms of vinegary odour and weak in alcohol odour. Weak odour was also detected for the faecal, rancid and cheesy odours. The 60 kg treatment was rated strong for wet sock odour due to poor drying condition. A significant difference (P < 0.05) was found between the 60 kg treatment and the lower loading treatments for pH and titratable acidity. A cut test showed that the lower loading treatments resulted in a higher percentage of brown beans. The 20 kg treatment showed the highest cut test score, which is significantly different (P < 0.05) from the 60 kg treatment. Fermentation index also showed a tendency for lower loading treatments to have a higher index. No significant difference (P > 0.05) was found among the treatments in terms of cocoa, astringency, bitterness and sourness flavour notes. However, better flavour was observed for beans from the 20 kg treatment. No mouldy off flavour was found in any of the dried beans. Overall quality assessment showed that the 20 kg treatment was able to produce reasonably good‐quality beans as compared to other loadings and therefore is recommended for the direct solar dryer. Copyright © 2006 Society of Chemical Industry