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141.
142.
分析了平朔矿区原有破碎机润滑系统使用中存在的问题,介绍了一种智能集中润滑系统的工作原理及其在平朔矿区应用中的系统配置、系统应用方案及系统维护。该智能集中润滑系统将PC和PLC与现场多点润滑泵、智能仪表和智能传感器相结合,采用多点润滑泵实现对破碎机多个点的集中润滑,采用电动加油泵实现自动补脂。实际应用表明,该智能集中润滑系统运行稳定、可靠,提高了设备使用效率,减少了日常维修工作量。 相似文献
143.
In this study, Adaptive Neuro-Fuzzy Inference System (ANFIS) has been used to model local scouring depth and pattern scouring around concave and convex arch shaped circular bed sills. The experimental part of this research study includes seven sets of laboratory test cases which were performed in an experimental flume under different flow conditions. A data set consists of 2754 data points of scouring depth were collected to use in the ANFIS model. The ratio of arch diameter, D, to flume width, W, is used as a non dimensional variables in all test cases. The results from ANFIS model were compared with the results of ANN model obtained by Homayoon et al. [24] and previously presented models. The results indicated that for D/W equal to 1 and 1.2, the ANFIS models produced a good performance for convex and concave bed sills. As a result, the ANFIS models can be used as an alternative to ANN for estimation of scour depth and scour pattern around a concave bed sill installed with a bridge pier. 相似文献
144.
Corrosion of iron-base alloys at 982°C (1800°F) by coal char is observed and the phase morphologies are discussed. No sulfidation was observed at 50 hr exposure. After 100 hr internal aluminum-rich sulfides were observed along with thick outer scales of iron oxide. The species causing the hightemperature-induced corrosion are probably sulfides and sulfates, present in most coal chars. Possible mechanisms for the corrosion are also discussed.Department of Materials Science and Mineral Engineering. 相似文献
145.
An examination of the influence of pressure and heating rate on the thermoplastic properties of a weakly coking coal and of coal with various pitch-like additives was carried out using a high pressure dilatometer. Pressure up to 4 MPa markedly increased the swelling properties and increased the plastic range by decreasing the softening temperature, but the effects of pressure were strongly influenced by rate of heating with high heating rates enhancing the effects. Additions of tar or pitch also enhanced swelling at low pressure. The solid carbonization residues from the dilatometer were examined by polarized light microscopy to determine the content and composition of optically anisotropic species. The anisotropic content was increased by increases in pressure and heating rate and pitch additives enhanced the anisotropic content, especially at low pressure, without affecting the composition of the anisotropy. No direct correlations exist between the dilatometric parameters and the optical anisotropy but their dependence on the conditions emphasizes that when considering high pressure gasification of coal, it is necessary to obtain data under appropriate conditions. 相似文献
146.
147.
Microwave plasma is studied as an alternative to oil or gas fuel for ignition and stabilisation of burning of lean coal. The study is performed on an experimental set-up, which includes a burner with a microwave plasma generator, coal and air supply systems, and measurement equipment. Power and thermochemical characteristics of the coal-plasma interaction have been measured and analysed. The obtained results indicate an essential intensification of ignition and combustion processes in the microwave burner compared to those in conventional burners. In particular, it has been demonstrated that the microwave energy consumption is only about 10% of the required expenditure of oil or gas, measured in heat equivalent. A design of an industrial microwave-plasma burner is proposed. Prospects of such burner for applications at industrial boilers of power plants are discussed. 相似文献
148.
A suite of density-differentiated macerals from several coals was analysed by Fourier transform infrared spectroscopy to obtain information on the nature and magnitude of the variations exhibited by the various maceral fractions. The most characteristic change between maceral groups was the variation in aliphatic hydrogen content, with exinite ? vitrinite ? inertinite. Since the separation technique (density gradient centrifugation) generally provided a number of fractions within a maceral group region, some of these were also analysed. In a series of density fractions from a low rank vitrinite, it was found that the aliphatic hydrogen content decreased as the density increased. The inertinites also exhibited a decrease in aliphatic hydrogen. The inertinite C—O bands had extinction coefficients different from those of vitrinites or exinites. The data suggest that quite profound variations in organic structure as determined by FT-i.r. spectroscopy can exist within a maceral group, so that for the most critical work on coals it is necessary to take this into account. 相似文献
149.
The relations between coke yields and the volatile matter content of 30 individual and 30 blended coals were investigated. Coke yields and deposited carbon related to volatile matter content can be expressed in the following equations: CY (%) = 97.89?0.86 VMch+VMc; and DC (%)= ?2.24+0.16 VMch; where: CY=real coke yield; VMch = volatile matter content of charging coal; VMc=volatile matter content of coke, and in the case of <2%; DC = deposited carbon. The test results show excellent correlation with practice. 相似文献
150.
Isao Mochida Hideichi Matsuoka Yozo Korai Hiroshi Fujitsu Kenjiro Takeshita 《Fuel》1982,61(7):587-594
Using low-rank coals, the modifying activities of some petroleum, coal tar and aromatic hydrocarbon additives have been examined to find procedures for their utilization in the preparation of blast furnace coke. Petroleum pitch, especially after hydrogenation, exhibited excellent modifying activity even with non-fusible coals. In contrast, the activity of coal tar was very limited with such coals. The napththenic component, revealed by n.m.r. of the additives, appears to be important in the co-carbonization by inducing fusibility and anisotropic development in such coals. Co-carbonization to recover the dehydrogenated additives was attempted. However, there was no development of the anisotropy in the resultant coke by dissolution of the coal particles although the coal particles were firmly fixed in the matrix. Acid-refluxing treatment of non-fusible coals was found to enhance their modification susceptibility, indicating that some of the acid-soluble mineral matter is important in the thermal depolymerization or fusion process of the coal. 相似文献