Fog Unit Research Articles

Small scale pellet boiler gas treatment in fog unit

The current research is aimed at experimentally finding out characteristic parameters of the operation of the fog unit and their effect on the efficiency of particulate matter capture. To conduct the experiment, a laboratory equipment—fog unit—was designed and prepared. The fog unit is suitable for 10, 20 and 30 kW pellet boilers. The impact of the parameters on essential changes of indicators important for PM capture is described: sprayed water and gas contact surface; droplets and gas contact time in the unit; droplets holdup in the unit. In the process, a regression equation for predicting the effectiveness of PM capture in a direct contact fog unit is obtained. A good experimental and calculated data correlation is observed (adjusted R squared statistics is 85.32%).

Treatment of Particulate Matter Pollution: People’s Attitude and Readiness to Act

Abstract The paper displays results of the questionnaire called “Particulate matter pollution in air”, which serves as a tool to determine level of public awareness of the health risks related to pollution from small capacity heating equipment in households. Barriers for installation of the innovative flue gas treatment technology called a fog unit in households and possible mechanisms to decrease or prevent these barriers were defined. The first part of the questionnaire included overall information about participants: age, gender, education level, place of residence, activities to protect the environment and motives behind performing these activities. The remaining questions were divided in four groups: “Environmental views”, “Knowledge on air pollution”, “Willingness to pay”, “Choice of flue gas treatment technologies”. The results of questionnaire correspond with raised problem situations. Over 80 % of respondents lack information on pollution and possible consequences deriving from it, and on potential solutions to prevent pollution. Residents of households are willing to pay for installation of flue gas treatment equipment (capital investments).

Innovative scrubber technology model for domestic boiler application

Many treatment technologies exist for particulate matter capture from the flue gas. Heat recovery from flue gases is a significant advantage of scrubber technology, which promotes energy efficiency increase of the combustion unit. The amount of recovered heat depends on heat and mass transfer in the scrubber. This paper presents the investigation of innovative small-scale flue gas treatment technology—fog unit. Households produce significant share of particulate matter in Europe. Therefore, there is a need to provide flue gas treatment technologies for domestic boilers in agreement with EU directive 2009/125/EC. Experimental research was done to identify the performance of proposed technology depending on inlet water flow rate, gas flow rate, water temperature, droplets diameter and water–gas flow ratio. The regression equations were developed based on performed data analysis. Equations can be used to predict the capacity of fog unit, outlet water temperature and outlet gas temperature.

Mathematical Modeling of Heat and Mass Processes in a Scrubber: The Box–Wilson Optimization Method

Optimal performance parameters must be found in order to organize efficient heat and mass transfer and effective flue gas cooling using a wet scrubber. Mathematical models are widely used for system optimization. However, a significant number of the available models have application limitations. This study presents a universal model for heat and mass transfer simulation in a scrubber called a fog unit, which has been developed and validated. Validation was performed by comparing the experimental and calculated results. Good agreement was achieved among the data, with differences between results not exceeding 10%. The model facilitates an investigation of the effects of gas flow, droplet size, and sprayed water on heat recovery from flue gas. An experimental matrix for fog unit capacity which included five main variables was designed and analyzed. The boundaries of the parameters are set considering the results of the experiments. The optimization method used is the path of the steepest ascent. The obtained results show the parameter change steps to achieve higher capacity of the condenser. In the studied unit, the maximum condenser capacity is limited by a flue gas flow value of 0.01 Nm3/s. The condenser optimization study that was conducted is viewed as a basis for further studies.

Toward Sustainable Micro-Level Fog-Federated Load Sharing in Internet of Vehicles

Advancement of technology has enabled access to innovative applications for connected devices. To handle growing computation requirements, the backend cloud data centers become an inefficient solution due to the caused network overhead. This is generally alleviated using edge locations deployed to meet the increasing computing demands. This article proposes a micro-level fog unit deployment to facilitate delay-sensitive applications. To manage imbalanced workloads due to the traffic density, the framework established a fog federation acting as a consortium where underutilized resources are shared to provide service quality. Moreover, we implement a price-based workload balancing algorithm to limit offloading among fog units relative to other consortium members. The experimental results show a balanced offload rate compared to traditional algorithms. Moreover, other measures, such as queue length, end-to-end delay, and workload balancing, demonstrate performance gain under the federation. Overall, 72% energy reduction is achieved through the proposed technique in comparison with the traditional nonfederated model.

Sprayed Water Flowrate, Temperature and Drop Size Effects on Small Capacity Flue Gas Condenser’s Performance

Abstract One of the main pollution types is air pollution, which has a significant impact on the surrounding environment and on living beings. Major source of air pollution is combustion processes. There are many flue gas treatment technologies around the world. In this paper a new, innovative flue gas treatment technology – fog unit – is introduced. The goal of the fog unit is to treat flue gases that are emitted from households. In the European Union, including Latvia, at the beginning of 2020, a directive will come into effect that will set limits for emissions and the effectiveness for incinerators in households. The main focus of this study was to determine the most optimal operating mode for the fog unit by changing different operating parameters: sprayed water temperature, sprayed water flowrate and types of nozzles (drop diameters). Results show that the most optimal operating mode in terms of flue gas treatment efficiency and recovered energy is at water temperature: 20 °C, sprayed water flowrate: 250 l/h and nozzle: MPL1.12 M. However, electrical consumption of water circulation pump leaves negative effect on this operating mode.

Experimental and analytical study of the flue gas condenser – fog unit

Abstract International organisations, unions and countries are taking part in reduction of pollutants from different sources by setting emission limits and boundary values for pollutants such as carbon dioxide, carbon monoxide, sulfur oxides, nitrogen oxides and particulate matter. According to EU Eco-design Directive each solid fuel household boiler technology has to include electric precipitator. A fog unit is a novel flue gas treatment technology made for small capacity combustion units. First experiments have been carried out in the fog unit experimental stand and results are analysed in detail. The capacity of the fog unit reached during experiments was between 1.02kW and 3.11kW, showing increase in efficiency from 5 to 15%. Data of experiments were used in a simulation (calculation) model, made for determination of fog unit capacity. Results of the model and experiments were compared and showed strong compatibility.

Particulate Matter Emission Decrease Possibility from Household Sector using Flue Gas Condenser – Fog Unit. Analysis and Interpretation of Results

Abstract Particulate matter (PM) is a significant pollution problem on the global scale. There are different ways to measure PM from stationary sources. The most used types of PM collection methods include different filters. These include cellulose, glass, mixed and membrane filters. In this study PM samples were measured in the flue gas condenser – fog unit system before and after the unit according to ISO 9096 standard using isokinetic and gravimetric method. PM concentrations after fog unit were measured at different water flows and nozzle types. Impact factors, that effect PM concentrations before and after the fog unit are listed and studied in detail. Achieved results show that the fog unit can be one potential technology for particle matter emission decrease from the household sector.

Laboratory research of the flue gas condenser – fog unit

International organizations, European Union, as well as countries on governmental levels are taking part in reduction of pollutants from different sources, including combustion equipment, by setting emission limits and boundary values for different pollutants such as carbon dioxide, carbon monoxide, sulfur oxides, nitrogen oxides and particulate matter. Each solid fuel household boiler technology has to include electric precipitator according to EU Eco-design Directive. A fog unit is a novel flue gas treatment technology made for small capacity combustion units. First experiments have been made in the fog unit experimental stand and results are analyzed in detail. The capacity of the fog unit reached during experiments was between 1.02 kW and 3.11 kW, showing efficiency from 5 % to 15 %.

Fog unit versus electrical precipitator and filter

Biomass takes an important place in the Latvian primary energy source balance. In the coming years steeper increase of the use of biomass for the production of heat can be predicted, in order to ensure the proportion of energy produced from renewable energy resources to 40 % in 2020. However, the use of biomass has increased the risk of environmental pollution, mainly with solid particles. In order to prevent an increase in quantity of particulate matter in the atmosphere, flue gas treatment is important, with special attention to small capacity boiler equipment. The research provides insight into innovative technologies for the flue gas treatment – fog unit. Technology comparison with another widely used flue gas purification methods are given in the article.

Study on the FOG-Based Well-Trajectory-Logging Tool

Summary The commonly used technology in well-trajectory logging, for both the oil and the gas well, is the magnetometer. However, it cannot work well in the magnetic-interfered or nonmagnetic environment, such as in a cased well or an iron mine. This paper presents a new trajectory-logging tool with a small diameter. Configured by a three-axis FOG unit and three quartz accelerometers, the logging tool allows for continuous attitude and trajectory measurement. High-temperature-caused accuracy degradation is the major error source for the underground environment. To diminish the thermal-related error, a flask stuffed with thermal-insulation material was embedded in the tool body; meanwhile, a wavelet neural network was used for identification of and compensation for the temperature drift. The system configuration, trajectory-resolution algorithm, and temperature-compensation algorithm are presented in this paper. Testing results show that the inclination accuracy is better than ±0.1°, with a range of 0 to 180°, and the azimuth accuracy is better than ±2°, with a range of 0 to 360°. The new logging tool resolves continuous trajectory-measurement problems in a magnetic-interfered or a nonmagnetic environment. Moreover, the capability of all-attitude measuring facilitates horizontal-well logging. Therefore, broad applications and good marketing could be anticipated for this new logging tool.

GraalBench

In this paper we consider implementations of embedded 3D graphics and provide evidence indicating that 3D benchmarks employed for desktop computers are not suitable for mobile environments. Consequently, we present GraalBench, a set of 3D graphics workloads representative for contemporary and emerging mobile devices. In addition, we present detailed simulation results for a typical rasterization pipeline. The results show that the proposed benchmarks use only a part of the resources offered by current 3D graphics libraries. For instance, while each benchmark uses the texturing unit for more than 70% of the generated fragments, the alpha unit is employed for less than 13% of the fragments. The Fog unit was used for 84% of the fragments by one benchmark, but the other benchmarks did not use it at all. Our experiments on the proposed suite suggest that the texturing, depth and blending units should be implemented in hardware, while, for instance, the dithering unit may be omitted from a hardware implementation. Finally, we discuss the architectural implications of the obtained results for hardware implementations.

Neuromuscular organization of avian flight muscle: architecture of single muscle fibres in muscle units of the pectoralis (pars thoracicus) of pigeon (Columba livia)

The M. pectoralis (pars thoracicus) of pigeons (Columba livia) is comprised of short muscle fibres that do not extend from muscle origin to insertion but overlap ‘in-series’. Individual pectoralis motor units are limited in territory to a portion of muscle length and are comprised of either fast twitch, oxidative and glycolytic fibres (FOG) or fast twitch and glycolytic fibres (FG). FOG fibres make up 88 to 90% of the total muscle population and have a mean diameter one-half of that of the relatively large FG fibres. Here we report on the organization of individual fibres identified in six muscle units depleted of glycogen, three comprised of FOG fibres and three comprised of FG fibres. For each motor unit, fibre counts revealed unequal numbers of depleted fibres in different unit cross-sections. We traced individual fibres in one unit comprised of FOG fibres and a second comprised of FG fibres. Six fibres from a FOG unit (total length 15.45 mm) ranged from 10.11 to 11.82 mm in length and averaged (±s.d.) 10.74±0.79 mm. All originated bluntly (en mass) from a fascicle near the proximal end of the muscle unit and all terminated intramuscularly. Five of these ended in a taper and one ended bluntly. Fibres coursed on average for 70% of the muscle unit length. Six fibres from a FG unit (total length 34.76 mm) ranged from 8.97 to 18.38 mm in length and averaged 15.32 ±3.75 mm. All originated bluntly and terminated intramuscularly; one of these ended in a taper and five ended bluntly. Fibres coursed on average for 44% of the muscle unit length. Because fibres of individual muscle units do not extend the whole muscle unit territory, the effective cross-sectional area changes along the motor unit length. These non-uniformities in the distribution of fibres within a muscle unit emphasize that the functional interactions within and between motor units are complex.