scholarly journals DEVELOPMENT OF ENERGY-EFFICIENT AND ENVIRONMENTALLY FRIENDLY LININGS AND THERMAL INSULATION OF ELECTRODE PRODUCTION FURNACES

2020 ◽  
pp. 21-34
Author(s):  
S.V. Leleka ◽  
Ye.M. Panov ◽  
A.Ya. Karvatskii ◽  
G.M. Vasylchemko ◽  
I.O. Mikulionok ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Thermal Insulation ◽  
Energy Efficient ◽  
Carbon Materials ◽  
Experimental Studies ◽  
Temperature Fields ◽  
Ecological State ◽  
Resource Saving ◽  
Oxidized Carbon ◽  
Carbon Monoxide Formation

A numerical analysis of the thermoelectric state of the Acheson furnace was performed and the use of new thermal insulation of blanks that are graphitized was proposed. The expediency of using a single-component heat-insulating charge as thermal insulation is shown. In this case, in comparison with the use of a traditional multicomponent synthetic mixture, not only a decrease in the temperature of the blanks is observed, but also a significant equalization of temperature along the axis of the blanks. Based on the results of measuring the thermophysical properties and numerical simulation of temperature fields in the volume of the Acheson graphitizing furnace, a resource-saving and environmentally efficient carbon heat-insulating mixture was selected, which consists of raw and graphite coke grains 50/50 % (wt.) up to 2 mm in size. Theoretical and experimental studies of the ecological state of kilns and graphitizing furnaces have been carried out. Based on the analysis of the obtained experimental data, the temperature and time dependences of the concentration of carbon monoxide in kilns and graphitizing furnaces are established. The main sources of carbon monoxide formation are determined: under-oxidized carbon materials, aromatic and resinous substances of binder preforms. A set of measures has been developed that can reduce the concentration of carbon monoxide emissions from furnace equipment in industrial conditions. Experimental studies were carried out to determine the temperature dependence of the concentration of carbon monoxide during heating of a multicomponent and one-component heat-insulating charge, which made it possible to establish a reduction in CO emissions by more than 20 % in the case of using the proposed one-component charge. Bibl. 17, Fig. 9, Tab. 3.

scholarly journals Determination of the Conditions for Carbon Materials Oxidation with Carbon Monoxide Formation at High Temperatures

2020 ◽  
Vol 14 (4) ◽  
pp. 545-552
Author(s):  
Yevgen Panov ◽  
◽  
Nikolai Gomelia ◽  
Olena Ivanenko ◽  
Andrii Vahin ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Carbon Materials ◽  
Carbon Oxidation ◽  
Packing Materials ◽  
Mass Unit ◽  
Definite Time ◽  
Charge Mixture ◽  
Carbon Monoxide Formation ◽  
Industrial Use

In this paper, the influence of carbon material type, temperature and oxygen concentration in gas mixture on the processes of carbon monoxide formation in production of the electrodes by graphitization was explored experimentally. Specific quantity of gas formed for a definite time, reduced to mass unit of carbon loading using pitch, packing materials and charge mixture of industrial use, was calculated. It is demonstrated that pitch provides the highest rate of carbon oxidation with the release of CO and substantially exceeds packing materials and charge mixture for this index.

scholarly journals Recent Advances in ZnO-Based Carbon Monoxide Sensors: Role of Doping

Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4425
Author(s):  
Ana María Pineda-Reyes ◽  
María R. Herrera-Rivera ◽  
Hugo Rojas-Chávez ◽  
Heriberto Cruz-Martínez ◽  
Dora I. Medina
Keyword(s):  
Carbon Monoxide ◽  
High Performance ◽  
Gas Sensing ◽  
Experimental Studies ◽  
Electrical Performance ◽  
Long Term Stability ◽  
Sensing Applications ◽  
Recent Advances ◽  
Sensitivity And Selectivity ◽  
Doped Zno

Monitoring and detecting carbon monoxide (CO) are critical because this gas is toxic and harmful to the ecosystem. In this respect, designing high-performance gas sensors for CO detection is necessary. Zinc oxide-based materials are promising for use as CO sensors, owing to their good sensing response, electrical performance, cost-effectiveness, long-term stability, low power consumption, ease of manufacturing, chemical stability, and non-toxicity. Nevertheless, further progress in gas sensing requires improving the selectivity and sensitivity, and lowering the operating temperature. Recently, different strategies have been implemented to improve the sensitivity and selectivity of ZnO to CO, highlighting the doping of ZnO. Many studies concluded that doped ZnO demonstrates better sensing properties than those of undoped ZnO in detecting CO. Therefore, in this review, we analyze and discuss, in detail, the recent advances in doped ZnO for CO sensing applications. First, experimental studies on ZnO doped with transition metals, boron group elements, and alkaline earth metals as CO sensors are comprehensively reviewed. We then focused on analyzing theoretical and combined experimental–theoretical studies. Finally, we present the conclusions and some perspectives for future investigations in the context of advancements in CO sensing using doped ZnO, which include room-temperature gas sensing.

Embedding metal foam into metal–organic framework monoliths for triggering a highly efficient release of adsorbed atmospheric water by localized eddy current heating

2021 ◽  
Author(s):  
Yingle Tao ◽  
Qiangqiang Li ◽  
Qiannan Wu ◽  
Haiqing Li
Keyword(s):  
Thermal Insulation ◽  
Eddy Current ◽  
Energy Efficient ◽  
Metal Foam ◽  
Low Cost ◽  
Metal Organic Framework ◽  
Atmospheric Water ◽  
Highly Efficient ◽  
Metal Organic ◽  
Eddy Current Heating

Localized eddy current heating delivered by metal foam embedded in a MOF monolith provides a novel, low-cost, and energy efficient way to overcome the thermal insulation nature of MOF monoliths and realize their highly efficient regenerations.

scholarly journals Opportunistic Large Array Propagation Models: A Comprehensive Survey

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 4206
Author(s):  
Farhan Nawaz ◽  
Hemant Kumar ◽  
Syed Ali Hassan ◽  
Haejoon Jung
Keyword(s):  
Energy Efficient ◽  
Large Scale ◽  
Performance Metrics ◽  
Experimental Studies ◽  
Cooperative Transmission ◽  
Analytical Models ◽  
Future Research ◽  
Large Array ◽  
Propagation Models ◽  
Comprehensive Survey

Enabled by the fifth-generation (5G) and beyond 5G communications, large-scale deployments of Internet-of-Things (IoT) networks are expected in various application fields to handle massive machine-type communication (mMTC) services. Device-to-device (D2D) communications can be an effective solution in massive IoT networks to overcome the inherent hardware limitations of small devices. In such D2D scenarios, given that a receiver can benefit from the signal-to-noise-ratio (SNR) advantage through diversity and array gains, cooperative transmission (CT) can be employed, so that multiple IoT nodes can create a virtual antenna array. In particular, Opportunistic Large Array (OLA), which is one type of CT technique, is known to provide fast, energy-efficient, and reliable broadcasting and unicasting without prior coordination, which can be exploited in future mMTC applications. However, OLA-based protocol design and operation are subject to network models to characterize the propagation behavior and evaluate the performance. Further, it has been shown through some experimental studies that the most widely-used model in prior studies on OLA is not accurate for networks with networks with low node density. Therefore, stochastic models using quasi-stationary Markov chain are introduced, which are more complex but more exact to estimate the key performance metrics of the OLA transmissions in practice. Considering the fact that such propagation models should be selected carefully depending on system parameters such as network topology and channel environments, we provide a comprehensive survey on the analytical models and framework of the OLA propagation in the literature, which is not available in the existing survey papers on OLA protocols. In addition, we introduce energy-efficient OLA techniques, which are of paramount importance in energy-limited IoT networks. Furthermore, we discuss future research directions to combine OLA with emerging technologies.

Carbon monoxide formation as an intermediate product in photocatalytic steam reforming of methane with lanthanum-doped sodium tantalate

2021 ◽  
Author(s):  
Wirya Sarwana ◽  
Akihiko Anzai ◽  
Daichi Takami ◽  
Akira Yamamoto ◽  
Hisao Yoshida
Keyword(s):  
Carbon Monoxide ◽  
Solar Energy ◽  
Steam Reforming ◽  
Intermediate Product ◽  
Room Temperature ◽  
Carbon Monoxide Formation ◽  
Steam Reforming Of Methane

Photocatalytic steam reforming of methane (PSRM) has been studied as an attractive method to produce hydrogen by utilizing photoenergy like solar energy around room temperature with metal-loaded photocatalysts, where methane...

Resource-saving Technologies and Some Proposals for the Creation of Automated Reclamation Systems

2021 ◽  
Vol 25 (7) ◽  
pp. 8-12
Author(s):  
Z.G. Lamerdonov ◽  
T.Yu. Khashirova ◽  
S.A. Zhaboev ◽  
L.Zh. Nastueva ◽  
A.А. Shogenov ◽  
...  
Keyword(s):  
Drip Irrigation ◽  
Salt Content ◽  
Experimental Studies ◽  
Soil Surface ◽  
Growing Season ◽  
Resource Saving ◽  
Water Savings ◽  
Irrigation Method ◽  
High Salt Content ◽  
Reclamation System

The results of experimental studies of the local subsurface irrigation method in comparison with drip irrigation carried out in the laboratory, which showed water savings due to a decrease in evaporation from the soil surface by 10–15 percent are presented. The method of irrigation in closed greenhouse farms using water with a high salt content is described. The paper proposes new patented schematic solutions for protecting plants from frost and pests, describes a multifunctional engineering and reclamation system capable of performing various operations depending on the emerging problems during the growing season.

Influence of Temperature Fields on the Quality of Dried Wood Products

2021 ◽  
Vol 1038 ◽  
pp. 336-344
Author(s):  
Olena Pinchevska ◽  
Andriy Spirochkin ◽  
Denys Zavialov ◽  
Rostislav Oliynyk
Keyword(s):  
Experimental Studies ◽  
Wood Products ◽  
Temperature Fields ◽  
Drying Process ◽  
Wood Moisture ◽  
Adequate Model ◽  
Heating And Cooling ◽  
White Spots ◽  
The Cost ◽  
Wood Heating

The reasons of white spots appearance in the middle of oak timber are determined. These white spots reduce the cost of the lamina made of oak timbers - the front covering of floorboards. It is proposed to intensify the drying process by using oscillating drying schedules to avoid this defect. A method for calculating the duration of such drying is proposed. This method includes the peculiarities of heating and cooling periods kinetics of oak timbers with 25 mm and 30 mm thickness. The inexpediency of using the oscillation of the drying agent parameters in the range of wood moisture content below 20% has been established. An adequate model for calculating wood temperature and air humidity during wood heating and cooling periods has been developed using heat and mass transfer criteria and experimentally determined oak wood moisture conductivity coefficient. Based on the results of theoretical and experimental studies oscillating drying schedules of different thickness oak timbers are offered. Tests of the proposed schedules in industrial conditions showed no discoloration of the central layers of European oak (Quercus robur) timbers. The drying process duration was reduced by 1.5–2.4 times and energy consumption were reduced by 1.53 times.

Sign in / Sign up

Export Citation Format

Share Document