Search results for "0204 chemical engineering"
showing 10 items of 273 documents
The Effect of Electric Field Configuration on the Thermo-Chemical Conversion of Straw Pellets
2020
Abstract With the aim to control and improve the thermo-chemical conversion of straw pellets, the experimental investigations of the DC electric field effect on the combustion dynamics and heat energy production were made. The electric field effect on the gasification/combustion characteristics was studied using three different positions of the positively charged electrode in flame. First, the electrode was positioned coaxially downstream the flame flow. Next, the electrode was positioned coaxially upstream the flame flow and, finally, the electrode was positioned across the downstream flow. The bias voltage of the electrode varied in the range from 0.6 up to 1.8 kV, while the ion current i…
Removal of Fe(III) from synthetic wastewater into raw and modified clay: Experiments and models fitting
2017
Water pollution by heavy metal ions has become a serious environmental issue especially due to their toxicity and tendency to bioaccumulation. Natural smectite clay was treated using sulfuric acid ...
Pressure-Induced Deformation of Pillar-Type Profiled Membranes and Its Effects on Flow and Mass Transfer
2019
In electro-membrane processes, a pressure difference may arise between solutions flowing in alternate channels. This transmembrane pressure (TMP) causes a deformation of the membranes and of the fluid compartments. This, in turn, affects pressure losses and mass transfer rates with respect to undeformed conditions and may result in uneven flow rate and mass flux distributions. These phenomena were analyzed here for round pillar-type profiled membranes by integrated mechanical and fluid dynamics simulations. The analysis involved three steps: (1) A conservatively large value of TMP was imposed, and mechanical simulations were performed to identify the geometry with the minimum pillar density…
A hierarchical model for novel schemes of electrodialysis desalination
2019
Abstract A new hierarchical model for the electrodialysis (ED) process is presented. The model has been implemented into gPROMs Modelbuilder (PSE), allowing the development of a distributed-parameters simulation tool that combines the effectiveness of a semi-empirical modelling approach to the flexibility of a layered arrangement of modelling scales. Thanks to its structure, the tool makes possible the simulation of many different and complex layouts, requiring only membrane properties as input parameters (e.g. membrane resistance or salt and water permeability). The model has been validated against original experimental data obtained from a lab scale ED test rig. Simulation results concern…
Thermal energy storage in granular deposits
2017
Energy storage technology is crucial for the development of the use of renewable energy sources. This is a substantial constraint, however it can, to some extent, be solved by storing energy in its various forms: electrical, mechanical, chemical and thermal. This article presents the results of research in thermal properties of granular deposits. Correlation between temperature changes in the stores over a period of time and their physical properties has been studied. The results of the research have practical application in designing thermal stores based on bulk materials and ground deposits. Furthermore, the research results are significant for regeneration of the lower ground sources for…
Internal heat gain from different light sources in the building lighting systems
2017
EU directives and the Construction Law have for some time required investors to report the energy consumption of buildings, and this has indeed caused low energy consumption buildings to proliferate. Of particular interest, internal heat gains from installed lighting affect the final energy consumption for heating of both public and residential buildings. This article presents the results of analyses of the electricity consumption and the luminous flux and the heat flux emitted by different types of light sources used in buildings. Incandescent light, halogen, compact fluorescent bulbs, and LED bulbs from various manufacturers were individually placed in a closed and isolated chamber, and t…
Numerical Investigation of a Wood-Chip Downdraft Gasifier
2019
Biomass gasification is regarded as one of the most promising technology in the renewable energy field. The outcome of such operation, i.e. the synfuel, can be exploited in several ways, for example powering engines and turbines, and is considered more flexible than the biomass itself. For this reason, a careful analysis of the gasification performance is of paramount importance for the optimization of the process. One of the techniques that can be used for such a purpose, is the numerical analysis. CFD is indeed a tool that can be of great help in the design and study of the operation of the gasifier, allowing for an accurate prediction of the operating parameters. In this work, a downdraf…
A study of solar panel efficiency in Latvian climate conditions
2020
With solar panels increasingly used in nearly zero energy building solutions it is important to clarify if the panels can achieve the efficiency indicators specified by their producers in real operation conditions. To determine the efficiency of poly- and monocrystalline panels depending on their spatial orientation and the seasons a set of test panels was installed in 2018 in Riga, Latvia for long-term monitoring of the amount of generated power and produced energy. Here we summarize the results of the first year of monitoring. Data indicate that orientation has high significance, very small amounts of energy are generated in autumn/winter and that there is a good correspondence of the act…
Influence of compression sportswear on recovery and performance: A systematic review
2018
Compression garments are becoming increasingly popular among sportspeople who wish to improve performance and reduce their exercise discomfort and risk of injury. However, evidence for such effects is scarce. This paper presents the evidence following a review of the literature evaluating the effects of the application of compression garments on sports performance and recovery after exercise. The literature reviewed was the result of a search on the Web of Science, PubMed, and SPORTDiscus electronic databases for studies which analysed the effect of compression garments on physiological, psychological, and biomechanical parameters during and after exercise. These search criteria were met b…
Running thermoregulation effects using bioceramics versus polyester fibres socks
2020
The feet, covered by socks and shoes during running, undergo an increase of temperature. The aim of this study was to reduce heat generation in the feet of athletes during running by wearing novel thermoregulatory socks impregnated with bioceramic materials. Thirty male athletes ran a half-marathon (21.0975 km) wearing polyester based with bioceramic fibres (zirconium silicate and titanium oxide) and control socks (polyester). The average temperatures were measured with a thermographic camera (FLIR e60bx) before and after the run. Nine regions of interests were evaluated in the plantar surface and eight in the dorsum. Before running, the plantar region with the highest temperature was the …