Simulation Model for the Model-Based Control of a Biofuel Dryer at an Industrial Combined Heat and Power Plant

The primary aim of this article is to present a simulation model for a bark dryer integrated into a combined heat and power plant. The same model can be used for the model-based control of the dryer. The secondary aim is to evaluate how useful the control is from an economic point of view. Results show that the final fuel moisture content can be stabilised by controlling the drying temperature(s). On the other hand, the deviation in final bark moisture decreases even when the dryer has no control at all. Net incomes resulting from drying increase in most cases compared to dryers without control. The need for control cannot be justified on economic grounds.     

DRYING OF SOY PULP (OKARA) IN A BED OF INERT PARTICLES

ABSTRACT

Drying of okara, an insoluble pulp residue waste byproduct of tofu production, was investigated in a continuously moving bed of inert particles subjected to vortex-like motion. The experimental variables in their respective ranges included the mass of Teflon pellets used as inert particles (0.4–1.2 kg), feed rate (0.5–1.4 kg/h), inlet air temperature (100–145°C) and airflow rate (195–271 m³/h). The dryer showed good performance in general and produced dry okara with moisture content ranging from 5 to 33% wb depending upon the operating conditions. The product recovery ranged from 80 to 90% on dry basis in most experiments. The specific water evaporation rate in okara drying increased with increasing of the feed rate and mass of Teflon pellets. However, the specific heat consumption decreased with an increase in the okara feed rate. Results showed that specific heat consumption for okara drying in a bed of inert particles was about 3 to 4 times higher in comparison with that of free water.     

MODELING VACUUM-CONTACT DRYING OF WOOD: THE WATER POTENTIAL APPROACH

ABSTRACT

A two-dimensional mathematical model for vacuum-contact drying of wood is presented. The moisture and heat equations are based on the water potential concept whereas the pressure equation is formulated considering unsteady state conservation equation of dry air. Most of the model parameters were determined during independent experiments. The set of equations is then solved in a coupled form using the finite element method. The validation of the model is performed using experimental results obtained during vacuum-contact drying of sugar maple sapwood. The experimental and calculated data are in good agreement. Nevertheless, some discrepancies are observed which can be attributed to the boundary conditions used and to the fact that heat transfer by convection was neglected.     

Optimization of Parameters for Microwave-Assisted Foam Mat Drying of Blackcurrant Pulp

Both analysis and optimization of parameters of microwave-assisted foam mat drying (MAFM), viz. microwave power, pulp load, drying time, and pulp thickness, for the dehydration process of blackcurrant pulp were performed in a household microwave oven. During MAFM drying, microwave power, pulp load, and drying time have positive effects on both vitamin C and anthocyanin content of blackcurrant pulp up to a certain level then a negative trend is observed. The increase of microwave power and decrease of pulp load accelerate the dehydration of blackcurrant pulp. The pulp thickness has a significant positive effect on both vitamin C and anthocyanin content of blackcurrant pulp. The optimum parameters valid for MAFM drying of blackcurrant pulp are as follows: microwave power of 560 W, pulp load of 65 g, drying time of 8 min, and pulp thickness of 4.46 mm. MAFM drying is a potential method for dehydrating blackcurrant pulp.     

Accelerated Mold Test on Dried Pine Sapwood Boards: Impact of Contact Heat Treatment

Abstract

We test the hypothesis that the combination of kiln drying of double-stacked boards and contact heat treatment will reduce the susceptibility of treated boards to colonization by mold fungi. Winter-felled Scots pine (Pinus sylvestris L.) sapwood boards were double-stacked in an industrial kiln in ‘‘sapwood out’’ and ‘‘sapwood in’’ positions. Dried samples were then contact heat-treated using a hot press at three different temperatures (140°C, 170°C, and 200°C) for three different periods (1, 3, and 10 min). An accelerated mold test was performed in a climate chamber where naturally mold-infected samples were used as a source of mold inocula. Contact heat treatment degraded the saccharides that accumulated at dried surfaces, and reduced the mold growth. The threshold temperature and time for inhibiting mold growth were 170°C for 10 min. However, for industrial application, the most feasible combination of temperature and time would be 200°C for 3 min. We concluded that double stacking/contact heat treatment used is an environmentally friendly alternative to chemicals for reducing mold on Scots pine sapwood boards.     

The Kinetics of the Sulphate Pulping of Gmelina arborea From Ghana

Investigations concerning the behaviour of Gmelina arborea wood growing in a plantation in Ghana by the Kraft delignification process were carried out in the St. Petersburg (formerly Leningrad) Academy of Forest Technology and Engineering in the Commonwealth of Independent States (Russia).

The basic kinetic data such as the rate constant, order of reaction, temperature dependence and the energy of activation were calculated. The kinetic data obtained indicate that the dielignification of G. arborea is by a process similar to that of diffusion as occurs during chemical reactions. Consequently, the delignification process at temperature which was carried out at selected cooking conditions is not solely controlled by kinetic processes.     

烟草中水溶性总糖与还原糖的分析研究进展

烟草中的水溶性总糖和还原糖对烟气的香吃味都有良好的作用,并能减少烟气的刺激性,对烟叶品质影响巨大,是决定烟叶品质的重要化学成分,是烟草化学常规分析中的重要项目.就烟草中水溶性总糖与还原糖的几种分析方法,如铜还原-滴定法、比色法、近红外光谱法、连续流动法等进行了综述,铜还原-滴定法是经典的方法,DNS定糖法建立了批量连续测定烟草样品中还原糖、水溶性总糖的方法,该方法具有快速省时、操作简便、试剂消耗少等优点,近红外光谱法是一种方便、高效、无污染、非破坏性、低成本的绿色分析技术,准确度高、操作方便,最新的烟草行业标准采用连续流动仪测定水溶性糖.以期对烟草中水溶性总糖与还原糖的研究具有一定的指导作用.     

Structural Investigation of the Binding of 5‐Substituted Swainsonine Analogues to Golgi α‐Mannosidase II

Golgi α‐mannosidase II (GMII) is a key enzyme in the N‐glycosylation pathway and is a potential target for cancer chemotherapy. The natural product swainsonine is a potent inhibitor of GMII. In this paper we characterize the binding of 5α‐substituted swainsonine analogues to the soluble catalytic domain of Drosophila GMII by X‐ray crystallography. These inhibitors enjoy an advantage over previously reported GMII inhibitors in that they did not significantly decrease the inhibitory potential of the swainsonine head‐group. The phenyl groups of these analogues occupy a portion of the binding site not previously seen to be populated with either substrate analogues or other inhibitors and they form novel hydrophobic interactions. They displace a well‐organized water cluster, but the presence of a C(10) carbonyl allows the reestablishment of important hydrogen bonds. Already approximately tenfold more active against the Golgi enzyme than the lysosomal enzyme, these inhibitors offer the potential of being extended into the N‐acetylglucosamine binding site of GMII for the creation of even more potent and selective GMII inhibitors.     

无焊接管道在年产200kt纸浆项目中的应用

对焊接管道、传统卡套式管接头和无焊接管道优、缺点进行对比分析,并结合装置特点,在制浆车间液压装置管道系统中成功应用了无焊接管道,避免了焊接管道、传统卡套式管接头之不足。     

包钢白云西铁精矿浆管道冬季焊接施工技术

详细介绍了包钢白云西铁精矿浆管道冬季焊接的施工技术,归纳了该技术的特点和原理,探讨了焊接操作要点,以系统学习和掌握管道焊接技术,丰富长输管线方面的施工内容。