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Recyclation of dust from production of dry mortar blends
Ondrůšková, Nela ; Novotný, Radoslav (referee) ; Šoukal, František (advisor)
The work deals with the problem of disposal of ever-increasing waste (dust) from the production of building materials and examines the possibility of recycling dust dust into cement repair mortar. The aim of this work was to determine the composition of individual dust particles from the production of cement mixtures and to determine their mechanical properties, as well as to determine the ideal ratio of dust particles to each other when mixing the dust mixture and its mechanical properties. This mixture consisted mainly of dust from products based on Portland cement, aluminous cement, gypsum and lime hydrate. The mixture further replaced part of the cementitious mortar and the impact of the additive on the mechanical properties of the cementitious mortar was determined. X-ray fluorescence spectrometry was used to determine the elemental composition, and X-ray diffraction analysis was used to determine the mineralogical composition. Test specimens were prepared according to the ČSN EN 12390 standard. Mechanical strength tests were performed on the test specimens. A large part of the test specimens could not be subjected to mechanical tests because the test specimen did not solidify even after a long time. The individual measurements that could be made show that the mechanical properties of the dust samples show values which have shown that the dust cannot be recycled into the product due to its instability. Dust particles have too diverse composition and in combination with cementitious repair mortar do not have the required properties. The problem is especially the sampling from the data, which did not solidify at all and thus excluded the remaining samples with already good properties of the same sample. When designing the method of recycling, it was necessary to take into account which product of the company is most in demand, where recycling would also make economic sense, which is also an important indicator for the operation of the company today. Dust particles could prove successful in another product, but it would not be advantageous for the company now, so now the recycling of dust particles will not start and they will be further disposed of in the same way.
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Solid Particle Emissions from AgroPellets Combustion
Svoboda, Marek ; Milčák, Pavel (referee) ; Lisý, Martin (advisor)
This thesis is divided into two parts. The first part deals with defining the main concepts, properties of biomass and pellets. Further, the procedures for measuring agropellets properties according to valid standards are mentioned. The following is a selection of the raw materials for the production of agropellet, with the determination of their properties. The theoretical part closes background research emissions from combustion and emission standards for a solid fuel boiler. The second part is an experimental one, which determines the formation of solid pollutants in combustion of four types of pellets made from alternative sources. Here are the graphs of the gaseous emissions of each of them. At last there will be a comparison of emissions agro pellets with more widespread wood pellets.
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Methods of Measuring of Particulate Matter Emissions
Bašta, Tomáš ; Brázdil, Marian (referee) ; Lisý, Martin (advisor)
This thesis deals with the methods applied for measuring the solid pollutants in the flue gases. It is divided into two main parts. The first part deals with the general problem of solid pollutants, methods of measurement and emission limits. The second part is devoted to the experimental measurements and determination of the mass concentration of solid pollutants in the flue gases of the combustion unit for solid fuels GEMOS 110. It shows the measurement procedure, necessary calculations and evaluations.
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Dust separators for small power boilers
Szweda, Martin ; Baláš, Marek (referee) ; Milčák, Pavel (advisor)
This thesis is divided into two parts. The first part of this thesis contains research on pollutants, separators and its legislation, while this part is focused on dust particles and their separation behavior. This is followed by a search on the different types of separators that can be used for small power boilers. The second part is followed by an experimental part, where the practical efficiency of the given separator is verified and then the measured values are compared and the result is evaluated. The results are used to determine whether the separator used is suitable for the separation of biomass for low-power boilers.
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Influence of dust particles on sliding contact
Píšala, Jan ; Janda, Marcel (referee) ; Veselka, František (advisor)
Master's thesis "effect of dust particles on sliding electrical contact" summarizes the sliding contact theory and praxe in rotating electrical machines. The principle of brush machines is described and the working environments are defined. The individual components of the sliding contact and reasons of their degradation are described in detail. Emphasis is placed on the influence of foreign particles, which can be assessed in practice by the method of dust particles. Furthermore, these theoretical knowledge was used in the practical assessment of the technical condition of various machines, as well as the called method. One set of brushes for the traction motor of the locomotive T47.0 was also experimentally innovated.
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Rizikové faktory v kabině sklízecích mlátiček
ŠTEMBERK, Martin
The diploma thesis is focused on harvesting threshers in terms of noise, dust and temperature in the cab. The work is divided into two parts, theoretical and practical. In the theoretical part there are basic data and concepts of harvesters, acoustic materials and health protection at work in agriculture. In the practical part itself was performed measurement of noise, dust, temperature and humidity in the cabin cabin cabinet. Measurements took place on land of agricultural cooperatives and private owners. Based on the measured values, an overview of the parameters of individual machines was created.
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Personal exposure to PM10 of selected workplaces in a coal strip mine determined by experiment
Basslerová, Barbora ; Hovorka, Jan (advisor) ; Hůnová, Iva (referee)
This thesis compares the experimentally determinated values of PM1, PM2,5, respirable fraction and PM10 between the cab drivers and the outdoor walkway of the bucket wheel excavator in the brown coal strip mine Doly Nástup Tušimice between March 16 and March 23, 2015. For the measurement of individual fractions, portable laser nephelometers were used. Superiority of coarse aerosol was confirmed outside from the total measurement time accounted for 82 %. PM10 fraction predominated outside and changed throughout the day depending on the activity carried out by a worker. Regular cleaning by sweeping stretches of dunes had an impact on PM10 concentrations. Fluctuations in the concentration of PM1 were detected in the driver cab due to smokers stay at this workplace. For these reasons there is a concentration difference between work shifts. Air temperature and relative humidity were also monitored in both types of work places. The air temperature average values reached over the range recommended for the optimal working environment in the driver cab. The thesis finds out personal exposure of a bucket-wheel excavator driver which is below the limit for the total concentration. Smaller fractions appears to be a potentially health risk. Powered by TCPDF (www.tcpdf.org)
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Laboratory Study of Field Ion Emission from Dust Grain
Jeřáb, Martin ; Šafránková, Jana (advisor) ; Stöckel, Jan (referee) ; Nehasil, Václav (referee)
Title: Laboratory study of field ion emission from dust grains Author: Martin Jeřáb Department: Department of Surface and Plasma Science Supervisor: Prof. RNDr. Jana Šafránková, DrSc., KFPP Abstract: Dust particles are common objects in space environment. As a dust particles, we call objects with typical sizes of several atoms up to approximately 100 µm. However, a total mass of dust particles is only about 1% of total mass of our galaxy, the presence of dust particles significantly affects environment. The most interesting is dynamics of dust particles and attached dust charging processes. The presented thesis consists of two main parts. The first part deals with the experimental study of field ion emission. Our measurements have been performed using gold and carbon spherical dust grains. It has been found that during the charging of dust particle using ion gun are the primary ions implanted under the surface of the dust particle from where they are release in the form of neutral gas. This releasing of implanted ions affects field ion emission for several hours. The second part of the thesis describes a development of new experimental apparatus determined to the study of photoemission dust charging and con- sequently to the "true" field ion emission study. Keywords: dust, dusty plasmas, charging properties, field...
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