This master´s thesis is dealing with the thermal calculation and design of boilers for natural gas combustion. The aim is to design the heating surfaces, so as to meet the requirements of the steam temperature of 490 ° C, the pressure of 7 MPa and the steam output of 60 t/h.

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第21373号 / 工博第4532号 / 新制||工||1706(附属図書館) / 京都大学大学院工学研究科化学工学専攻 / (主査)教授 前 一廣, 教授 河瀬 元明, 教授 佐野 紀彰 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

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Current methods to reduce the native microbiota and potential pathogens on spices include steam treatments and ethylene oxide (EtO) fumigation. The objectives of this research were to identify the effectiveness of a lab-scale steam apparatus and a commercial EtO process on the inactivation of Salmonella enterica or Enterococcus faecium NRRL B-2354 inoculated whole black peppercorns and cumin seeds. Peppercorns and cumin seeds were inoculated with Salmonella or Enterococcus and processed in a lab-scale steam apparatus at 16.9 PSIA and two references temperatures (165°F and 180°F) and in a commercial ethylene oxide fumigation chamber using a standard commercial EtO fumigation process. Cells were enumerated by serial dilution and plating onto TSA with a thin overlay of selective media. Inoculation preparation influenced inactivation of Salmonella on peppercorns with greater reductions reported for TSA-grown cells compared to within a biofilm. To achieve an assured 5-log reduction of TSA-inoculated Salmonella on peppercorns exposure for 125s and 100s at 165°F and 180°F, respectively is required. For cumin seeds temperatures of 165°F for 110s were needed or 65s at 180°F to assure 5 log reduction. EtO fumigation significantly reduced both microorganisms on both spices (p<0.05), however significant variation existed between bags in the same process run. Reductions of Enterococcus were comparable or less than that of Salmonella under the majority of conditions, however a direct linear relationship cannot be used to compare the microbes. This study demonstrates that the effectiveness of Enterococcus faecium NRRL B-2354 as a surrogate for Salmonella can vary between spices and processes. / Master of Science in Life Sciences

M.S.

The topic of thesis is condensing turbine in gas-steam cycle, which can be divided into four basic parts. A history of gas-steam cycle is described in the beginning. Second part is all about calculation of heat recovery steam generator. Penultimate section deals with calculations of steam turbine parameters and reaction blading type. Last part contains electric power and steam turbine efficiency.

The work deals with the design of a system of orifices for high pressure difference. The task of this work is to design a device for controlled discharge of steam-gas mixture from a volume compensator with an overpressure of 12,27 MPa to a tank with an overpressure of 0,02 MPa at a constant mass flow of 40 kg/h. The first part of the thesis contains the theory and also the basic principles of calculations. In the next part of the work, the theoretical properties of flow, such as the speed of sound in wet steam, are determined. This knowledge then serves the main goal of the work, namely to design a system of orifices to release steam-gas mixture from the volume compensator.

This master’s thesis is dealing with design of steam boiler for wood chips. Wood chips are considered as biomass and so the steam boiler is considerate to enviroment. Main purpose of this work is calculation of size and number of water/steam heating surfaces so the boiler can produce steam with required parametres of temperature, pressure and amount.

The aim of this Diploma thesis is design of steam boiler with steam reheating, for combustion the blast furnace gas. The fuel composition and primary parameters for calculation of the boiler were provided. In the first part the fuel composition is described. The main part of the thesis consists of stoichiometric calculations, establishing efficiency of the boiler, calculating combustion chamber as well as design and calculation individual heating surfaces. Part of the work is also drawing documentation of boiler.

The Diploma’s thesis deals with calculation of tree heat schemas with condensing steam turbine with uncontrolled steam extractions for regeneration – tree low pressure heaters, two high pressure heaters and a deaerator. Heat schemas are compared to each other according to reheat pressure. The most efficient schema is used to steam turbine thermodynamic design – design of control stage and blade stages. At the end of diploma thesis a stress analysis of the last rotor blade is made.