China
Africa
Explore chapters and articles related to this topic
Self-Heating Conductive Cement-Based Nanomaterials
Published in Antonella D’Alessandro, Annibale Luigi Materazzi, Filippo Ubertini, Nanotechnology in Cement-Based Construction, 2020
E. Seva, O. Galao, F. J. Baeza, E. Zornoza, R. Navarro, P. Garcés
Electrical heating involves passing an electrical current through a resistance as a heating element. With respect to the heating of buildings and other structures, heating involves embedding heating elements in the materials used in the construction, such as concrete or gypsum. Materials used as heating elements are typically metal alloys, such as nickel-chrome. The metallic fibers are embedded in the structural material in order to attain heating through resistance. However, this procedure degrades the mechanical properties of the structural component, rendering difficult the repairing of the heating elements. Moreover, embedding these elements in the structural components results in non-uniform heating as it is limited to selected areas. The non-uniform heating worsens due to the poor thermal conductivity of structural materials. A conductive cementitious material, by the addition of a carbon-based material, can be used as a resistor—the Joule effect—and, therefore, as a heating element. There is no need to embed fibers in a structural element, which, in turn, minimizes the aforementioned problems. The resistivity of conventional concrete is too high to provide effective electric resistance heating; however, by the addition of carbon-based materials, such as carbon fibers, it is possible to reduce the electrical resistivity to adequate levels.
Heat Sources for Deployment of CHEM Products
Published in Witold M. Sokolowski, Cold Hibernated Elastic Memory Structure, 2018
Witold M. Sokolowski, Jeng-Neng Fan, Carl de Smet
The surface-mounted method was selected for further investigation. In this area, several types of heating elements could be used: etched-foil flexible heater, wired heater, and nickel-coated carbon-fiber heater. These flexible heaters can be heated up to a temperature around 70°C–250°C, which is enough to reach the Tg of the CHEM structure. The nickel-coated carbon-fiber heater has the best temperature uniformity, but it is the most expensive one. The etched-foil flexible heater has the most economic cost among three but has worse temperature uniformity compared with the nickel-coated carbon-fiber heater. Since the heating issue in the CHEM sandwich panel was not so critical, the etched-foil flexible heater was selected.
Electrical fundamentals
Published in David Wyatt, Mike Tooley, Aircraft Electrical and Electronic Systems, 2018
The effects of electric current flow can be detected by the presence of one or more of the following effects: light, heat, magnetism, chemical, pressure and friction. For example, heat is produced when an electric current is passed through a resistive heating element. Light is produced when an electric current flows through the thin filament wire in the evacuated bulb of an electric lamp.
Investigation of heat transfer and damage characteristics of high pressure abrasive water jet impacting high temperature sandstone
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2023
Jianguo Zhang, Yingwei Wang, Jianming Shangguan, Zehua Niu, Rui Min
For metal ores buried at greater depths (>3 km), the ore rock temperatures typically exceed 100°C. In order to approximate the real deep ground high-temperature environment, the experiments were set up with three sets of sandstone heating temperatures of 250°C, 300°C and 350°C. The heating device is SX2–10-12A box muffle furnace. The device adopts resistance wire heating element for heating, and the maximum temperature can reach 1200°C. It has the characteristics of subsection setting of heating path, real-time measurement and display of furnace temperature and continuous adjustable heating rate. The rock samples are first heated to a preset temperature at a heating rate of 60°C/h to prevent thermal shock to the rock during the heating process (Chen et al. 2012; Yin, Li, and Li 2019), and after heating to the target temperature, they are kept at a constant temperature in the furnace for 2 hours to ensure uniform heating of the rock.
Experimental testing of fly ash containing recycled aggregate concrete exposed to high temperatures
Published in Sustainable and Resilient Infrastructure, 2022
Muhammad Masood Rafi, Tariq Aziz
An electrical heat treatment furnace with a digital control panel (Figure 1) was used for heating the concrete specimens. The internal size of the furnace chamber is 1500 × 750 × 750 mm with a capacity of 870 L. The chamber is lined with high-grade insulating bricks. The temperature inside the furnace chamber is controlled by the electrical heating elements which are placed on all four sides of the furnace chamber. A digital display with a control panel indicates the temperature inside the chamber. Type S thermocouples are provided to monitor the internal environment of the furnace. A double-glazed quartz viewing port of 100 mm diameter allows viewing the specimens inside the furnace. The heating elements are able to raise the temperature inside the furnace up to a maximum of 1200°C.
Effects of Al2O3 content on the properties of BF slag and suitable fluxing regime for BF ironmaking with high Al2O3 content
Published in Canadian Metallurgical Quarterly, 2023
Chen Buxin, Hou Jian, You Yang, Pan Yuzheng, Bai Chenguang, Zhang Shengfu, Hu Meilong
The rotating cylinder method was used to measure viscosity of slag in the present study [16]. The experimental arrangement including the dimensions of the crucibles and spindle is shown in Figure 1. It consists of a control cabinet, a high-temperature heating furnace, a software system and a Brookfield digital viscometer. The heating element is a silicon molybdenum rod, and the maximum temperature can be heated to 1650°C. During the experiments, the slag sample was loaded in a molybdenum (Mo) crucible and placed the Mo crucible in a corundum crucible, a graphite crucible was used as the outer layer to remove the remaining oxygen in the furnace. The rotating bob was made of Mo.