Study on the Synthesis of SiC Powder Material by Using Induction Heating System

2020 ◽  
Vol 1014 ◽  
pp. 38-42
Author(s):  
Fang Jiao ◽  
Zhou Li Wu ◽  
Dian Peng Cui ◽  
Mu Long Yang ◽  
Bo Yu Dong

By using a NAURA Advanced Physical Vapor Transport (PVT) System, the character ofthe synthesized SiC powder were studied. Mainly from the aspects of purity and particle size, and relevant experiments were designed to understand the influence of the powder source on the synthesized SiC powder. The results showed that the selection of Si powder source with appropriate particle size was conducive to increase the proportion of large particle size of SiC powder. In addition, the purification of material source in the early stage of the process was beneficial to improve the purity of SiC powder. The results showed successful preparation of optimized SiC powder and thus high-quality SiC wafers were made.

1939 ◽  
Vol 31 (12) ◽  
pp. 1509-1512 ◽  
Author(s):  
J. McGavack

Author(s):  
Stanislav Chicherin

Introduction. Renovation of housing stock supposes construction of new buildings, where the main utilities consuming heat energy will be heating and hot water supply (HWS) systems. Under such conditions the task of heat consumption reduction by transfer to low-temperature and use of the associated procedures is relevant. Materials and Methods. Research was performed on the basis of residential and administration buildings designed within the whole Russia, the facilities were selected based on the year of putting into operation and their purpose. The source of data concerning buildings became documents included into the scope of the design and detailed documentation: plans, drawings and explanatory notes. As meeting the demands of hot water supply makes the main contribution to daily nonuniformities of heat energy consumption, the attention was paid to equipment of hot water supply systems. For calculations, the commercial product of Microsoft Office Excel 2010 was used. Results. During selection of roof boiler house as a source of heat supply increase in consumption of equivalent fuel in relation to the variant of connection to heat power plant operating on solid fuel by 187,314 tons of fuel oil equivalent is possible. General refusal from power-and-heat generation complicates operation of large district heat supply systems. The design parameters of coolant in building heating system differ from project to project: from 95/70 °С, used everywhere till the beginning of the XXI century, up to 90/65 °С corresponding to existing practice of designing or 80/60 °С as at the facility in Sevastopol. Reduction of design temperatures by 5 % is insufficient to decrease general heat consumption of the building. Reduction of heat consumption is explained by selection of advanced materials for pipeline heat insulation. Use of automation diagrams for heat points on the basis of regulator ECL Comfort 310 contributes to improvement of hydraulic control for heating systems, however, concealed automation results in violation of high-quality mode for heat network control and decrease of coolant parameters on adjacent (often non-automated) consumers. Conclusions. Supplement of central high-quality control by local constant temperature/variable flow control at individual heat unit and installation of temperature controllers on heating radiators with mechanical thermostatic head have potential for reduction of the heat energy volume used ineffectively. Increase in level of controllability for heating system together with cheaper and responsive automation systems are basic conditions for increase in quality of heat supply in future.


Fuel ◽  
2021 ◽  
Vol 289 ◽  
pp. 119838
Author(s):  
Xiaogang Mu ◽  
Jinfang Liu ◽  
Fei Gao ◽  
Cunbao Deng ◽  
Zhixin Jin ◽  
...  

2001 ◽  
Vol 3 (7) ◽  
pp. 773-780 ◽  
Author(s):  
Samia Ferchiche ◽  
Juliusz Warzywoda ◽  
Albert Sacco

2018 ◽  
Vol 68 (332) ◽  
pp. 169 ◽  
Author(s):  
S. Ramjan ◽  
W. Tangchirapat ◽  
C. Jaturapitakkul

This research aimed to study the effect of finenesses of bagasse ash (BGA) on the alkali-silica reaction of mortar. The BGA sample was ground to have particles retained on a sieve No. 325 of 33±1% and 5±1% by weight. Ground BGA samples were used separately to replace ordinary Portland cement (OPC) at rates of 10, 20, 30 and 40% by weight of binder to cast mortars. The compressive strengths and the alkali-silica reaction (ASR) of mortars were investigated. The results showed that a large particle size of BGA is not suitable for use in lowering ASR because it results in a low compressive strength and high expansion due to ASR. The mortars containing BGA with higher fineness exhibited higher compressive strength and lower expansion due to ASR than the mortars containing BGA with lower fineness. The results also suggested that the ground BGA retained on a sieve No. 325 of less than 5% by weight is suitable to be used as a good pozzolan which provides high compressive strength and reduces the expansion of mortar due to ASR even though it contains high LOI. The obtained results also encourage the utilization of ground BGA effectively which leads to reduce the disposal of bagasse ash.


2005 ◽  
Vol 11 (22) ◽  
pp. 53-58
Author(s):  
Akihiro MAEGAWA ◽  
Toshihiko SHAKOUCHI ◽  
Yukihisa YUASA ◽  
Naoki MISHIMA ◽  
Shigemitsu HATANAKA

Water ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2698
Author(s):  
Xiangming Jiang ◽  
Shuang Hui ◽  
Wanghua Sui ◽  
Zhiyuan Shi ◽  
Jiahao Wang

This paper presents an experimental and field investigation on the efficiency of plugging by pouring aggregate in different sequences through multiple boreholes in a tunnel with flowing water. There have been controversies surrounding the selection of the pouring order for different particle sizes of aggregates and the order in different boreholes. A visualized experimental setup is used to investigate the influence of the pouring orders on the efficiency of plugging through multiple boreholes under the flowing-water condition. A case study of the salvage of a flooded mine using ground directional boreholes was investigated and compared with the experimental results. The water-pressure difference at the aggregate-capping moment, when fine aggregate was poured first and coarse aggregate later, was relatively small, compared to that when fine aggregate was poured upstream and coarse aggregate, downstream. The result implies that the efficiency of plugging with the order of pouring fine aggregate first and coarse aggregate later in different boreholes is better than that with the order of pouring fine aggregate upstream and coarse aggregate downstream. When the poured aggregate is about to be capped, increasing the pouring intensity with the same or a larger particle size is more conducive to capping. The case study shows that pouring fine materials in the early stage reduced the cross-sectional area; in the later stage, the aggregate particle size was gradually increased, which can be helpful in forming an effective water-barrier section in the tunnel. The pouring of aggregate provided a base for cement grouting to form a water-plug section with a length of 106 m, resulting in a sealing efficiency of 100% for the case.


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