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1.
现有的陶纤毡加热炉运行多年,热效率降低,维护工作量较大。通过实施更换改造后,大大提高了加热炉的效率,降低了生产成本及维修费用,是提升企业经济效益和竞争能力的必然选择。  相似文献   

2.
在硫酸电加热炉改造中,以0Cr25A15铁铬铝合金丝取代原管式电加热元件,并采用可控硅自动控制加热温度。该电炉投资省,简单,可靠,高效,配置灵活。  相似文献   

3.
本文分析了提高管式加热炉热效率的方法和措施,并以炼厂管式加热炉节能改造为例,说明了加热炉节能改造的必要性。  相似文献   

4.
参照武汉化工二厂管式加热炉的改进方案,通过对管式炉的热过程分析,选择合理的物料走向,将我厂老式方箱炉进行改造,从而提高了传热效率。  相似文献   

5.
通过对催化重整装置四台圆筒炉的瓦斯喷枪进行改造,H102、H103对加热炉辐射室喷涂高温辐射涂料,有效地降低了炉膛温度和排烟温度,减少了瓦斯用量,提高了炉子的热效率;对重整三合一加热护辐射室衬里进行了更换,有效地降低了炉壁表面温度。  相似文献   

6.
对马寨联合站炉效过低卧式水套加热炉,进行了内部加超导管改造,录取各种资料对改造前后的效果进行了对比,总结出加热炉内部安装超导管所取得的效果非常明显。证明此方法是有效的。  相似文献   

7.
李世宏 《化肥设计》2002,40(2):44-46
分析原有回转式空气预热器存在的问题及原因,介绍选用无机热传导式空气预热器进行改造的方案及特点,总结了改造效果。  相似文献   

8.
主要介绍了石油二厂南蒸馏的发展史和本次改造的目的,分析原装置存在的问题,并提出改造(原油换热系统、加热炉,常压塔)的措施。此次装置技术改造,不但解决了装置的生产瓶颈,使日处理量由改造前的6000t提高到了改造后的8400t以上,能耗相对降低,而且各侧线产品质量和收率也得到了明显的提高。同时还改善了操作条件,提高了生产的平稳性,达到了改造的目的。  相似文献   

9.
通过介绍了管式加热炉和导热油加热炉系统的工作原理,对两种加热炉的优缺点进行了对比,并根据其在长输管道中的应用情况进行了总结。  相似文献   

10.
本文介绍了对电加热炉改造前后的应用效果,并对其作了简要分析。  相似文献   

11.
为了探究不同岩性、不同级配机制砂对混凝土性能的影响,对三种不同岩性机制砂混凝土及天然河砂混凝土的工作性和抗压强度进行研究。此外,对比分析了四种混凝土在干湿循环制度下的抗硫酸盐侵蚀性能。结果表明,天然河砂混凝土的工作性优于机制砂混凝土,钙质机制砂混凝土的工作性略好于硅质机制砂混凝土。机制砂混凝土的抗压强度优于天然河砂混凝土,在硫酸盐侵蚀循环作用下的力学性能变化趋势与天然河砂混凝土基本一致。在相同级配条件下,机制砂混凝土的抗蚀系数高于天然河砂混凝土;机制砂岩性并不会对混凝土抗硫酸盐侵蚀性能带来负面影响。级配良好的机制砂可以增强混凝土抗压强度和抗硫酸盐侵蚀性能。  相似文献   

12.
The measurement of functionality of protein food ingredients has developed somewhat haphazardly, probably due to the wide range of proteins used as ingredients and the diversity of foods. Studies of the physiochemical properties of proteins should enable prediction of a proteins response to process environments and prove more fruitful than many of the empirical measurements of functionality. The effects of pH, salt type and concentration on the phase behaviour of the oilseed globulin and arachin, demonstrates the complexity of protein solubility and the inadequacies of simple tests that have arisen. Studies of the effects of salts and conditioning on meat fibres, coupled with measurement of the location of water in pellets from water holding tests enable the latter to be applied with increased confidence. Comparison of the endothermic transitions observed on heating with the development of storage and loss moduli allow the contributions of domains of skeletal muscle myosin to gel structure to be investigated.  相似文献   

13.
Six electrophysiologically active aromatic compounds, viz., anisole, benzaldehyde, veratrole, guaiacol, phenylacetonitrile, and phenol, were identified in the volatiles of older-adult male desert locust. Young adults and females of all age groups produced none or only trace quantities of these compounds. Comparison of the aggregation responses of young and older adults to the crude, older-adult, volatile extract and different synthetic blends of the six compounds showed that the aggregation pheromone system of the adult gregarious locust consists of phenylacetonitrile, guaiacol, phenol, and benzaldehyde. Like the crude volatile extract of older males, neither the synthetic blend of the six compounds nor the adult pheromone blend evoked any significant aggregation responses from nymphs. These results confirm our previous report of sexual differentiation in the production of adult aggregation pheromone in the desert locust and of the evidence of two distinct aggregation pheromone systems in the two stages of the insect.  相似文献   

14.
Molecular mechanics modelling is used to calculate the energies of interaction, hence the molecular level energy of adhesion at the interface with crystalline cellulose I of three different photopolymerizable primers and of a polyester varnish at the interface with the primer/cellulose assembly. The energy of interactions for just one of the primers with the statistically most common conformation of amorphous cellulose has also been obtained for comparison. Experimental results of adhesion by a standard peel test and by thermomechanical analysis, in which the effect of viscoelastic energy dissipation by crack tip propagation has been respectively minimized or is not present, hence in which the energy of interfacial interaction is nothing else but the work of adhesion, correlated well with the energies of interaction calculated by molecular mechanics. An equation correlating the energy of interaction at each finish/cellulose interface with the deflection derived by thermomechanical analysis, and with the number of internal bond rotational degrees of freedom as well as the degree of networking of the finish, has been derived and is presented. A relationship between the intrinsic fracture energy Go and the molecular mechanics-derived energy of interaction at the interface equating this to the square of the work of adhesion is obtained and is presented.  相似文献   

15.
Isoprenoids and phenolics, major metabolites of important browse species, are reviewed in regard to concentrations, distribution within tissues, and between species. Seasonal variation of specific substances and changes with age of the plant are also considered. The distribution of substances may affect food selection and feeding behavior of animals. Wild mammalian herbivores tend to avoid plant parts rich in these substances, in spite of high nutritional content of the plant tissue. Possible mechanisms for defense by plants against depredation by mammalian herbivores are discussed within the framework of the plants' biochemistry.  相似文献   

16.
17.
使用共沉淀法制备负载Cu催化剂。通过添加碱土金属Sr,对Cu催化剂进行了改性,以提高Cu催化剂在果糖加氢制备甘露醇过程中的活性和选择性。采用ICP-MS、TEM、XRD、H2-TPR、XPS和CO2-TPD等对所制备的催化剂进行了系统表征。结果表明:Sr的添加能增大催化剂的比表面积,促进活性组分Cu的分散,从而提高了催化剂的活性,并且增加了催化剂的碱性,使果糖优先形成β-呋喃糖中间体,从而提高了甘露醇的选择性。在果糖浓度为1.1 mol·L-1、催化剂用量为反应物质量的6%、反应温度为373 K、反应氢压为4.0 MPa、Cu/Sr原子比为7∶1的反应条件下,果糖转化率为99%,甘露醇的选择性为79%。催化剂循环使用了20次,其催化稳定性基本保持不变。  相似文献   

18.
密封界面的泄漏机理是机械密封研究与应用的焦点问题之一,涉及泄漏通道表征、粗糙表面的接触力学模型、界面微观形貌变化以及介质流体在泄漏通道中的流动阻力等问题。回顾了近几十年国内外接触式机械密封泄漏通道模型的研究,深入分析了G-W模型、M-B模型和Persson模型3种粗糙表面接触力学模型的贡献和存在的问题,提出了一种基于逾渗理论的泄漏通道新模型;探讨了密封界面的分形参数、泄漏通道的流动阻力以及密封界面的有限尺寸效应对泄漏特性的影响,指出孔隙连通贯穿界面和流体流经贯穿通道的流动阻力小是密封界面产生泄漏的成因,以及泄漏通道的形成和泄漏通道内的流体流动特性是泄漏机理研究的主要方向。  相似文献   

19.
Experimental trials of the water hydrolysis of bagasse to produce xylose, arabinose and glucose were conducted using a temperature-controlled microwave digester. The experimental variables were temperature, ratio of water mass to bagasse mass, type of bagasse material and reaction time. The pH of the liquid and concentration of dissolved xylose, arabinose and glucose were measured at the completion of each trial. Kinetic modelling of the global rates of formation of monosaccharide products was performed using schemes based on earlier researchers’ models of acid hydrolysis using mineral acids. For the most plentiful product, xylose, the most accurate kinetic model of the global reactions was determined to be two parallel pathways for hydrolysis of xylan to xylose followed by a single pathway for xylose decomposition. The calculated activation energies of the reactions were within the range reported by other researchers for the hydrolysis of a range of lignocellulosic materials using mineral acids.  相似文献   

20.
The rate of hydrolysis of the abundant foliar protein, ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBPC), in enzymatically active gut fluid ofManduca sexta larvae is very rapid and is unaffected by the presence of tannic acid, even when tannic acid is present in the incubation mixture in amounts in excess of the amount of RuBPC. When this protein is dissolved in the denatured gut fluids ofM. sexta larvae orSchistocerca gregaria nymphs, large amounts of tannic acid must be added to bring about the precipitation of significant quantities of protein. The ability of insect gut fluid to prevent the formation of insoluble tannin-protein complexes is due to the presence of surfactants. On the basis of our results and a review of the findings of other investigators, we argue that there is no evidence that tannins reduce the nutritional value of an insect's food by inhibiting digestive enzymes or by reducing the digestibility of ingested proteins and, further, that the failure of tannins to interfere with digestion is readily explained on the basis of well-documented characteristics of the digestive systems of herbivorous insects. In challenging the currently popular notion that tannins are digestibility-reducing substances, we do not challenge the general utility of either the apparency theory or resource availability theory of plant defense. In debating the merits of these two analyses of plant-herbivore interactions, however, the demise of tannins as all-purpose, dose-dependent, digestibility-reducing defensive substances must be taken into account.  相似文献   

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