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Manufacturing possibilities of sparking plug body
Strnad, Miroslav ; Kopřiva, Miloslav (referee) ; Podaný, Kamil (advisor)
Difficulties of manufacturing sparking plug body are analyzed in this thesis, which aims to select the most appropriate option. Body is circular section of steel 1.1191 (12 050), with a hole in the middle and upper part of this body is ended with hexagonal shape. The series is estimated at 1 000 000 units per year. For the production of sparking plug body are selected options from the machining and forming technologies. Specifically, turning and milling, casting, forging, a method using superplastic material and cold extrusion. Selected technologies will be reviewed based on cost to produce one piece, time requirements of manufacture of the unit, material usability and overall feasibility. According to these parameters forming is chosen as the best option.
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Manufacturing possibilities in cold forming procesess
Trnka, Filip ; Podaný, Kamil (referee) ; Šlais, Miroslav (advisor)
This project is elaborated in the bachelor's degree field of engineering technology. The main objective of this work is the chosen technology for cold forming their valuation and illustrative examples of products manufactured as follows. There are presented examples of unconventional types of technologies and concludes with a brief overview of companies dealing with cold-forming, with examples of their products and their uses.
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Forming technology production of window hanger.
Štejnar, Radek ; Šlais, Miroslav (referee) ; Forejt, Milan (advisor)
An objective of the bachelor’s thesis is the solution of forming technology production of window hanger by means of backward extrusion and elaboration of study concerning cold bulk forming. Required component is made of material ČSN 41 1320 5R and rounded chock with dimension of 14,6h9 - 25,3 mm is selected as semifinished product for production. Generally 2 alternatives of technology process were assessed whereas technological and strength calculations are executed utilizing computing support of TVÁŘENÍ and OPTIM97 software. Component is produced within 4 operations including cutting of wire. Multi-stage cold forming press TPZK 25 made by ŠMERAL a.s. Brno producer was chosen for designed technology. Production tools are made of high speed tool steel 19830.
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Testing of processing stability of PP-g-IA
Hampapa, Břetislav ; Tocháček, Jiří (referee) ; Kučera, František (advisor)
The Bachelor’s study is interested in processing stability of polypropylene grafting with Itaconic anhydride. A present knowledge about thermal degradation of Itaconic derivatives was summarized in theoretical part. Samples were prepared by multiple extrusions technique from virgin PP (Borsodchem, Hungary) and PP-g-IA. Die temperature 230 °C, processing time 4 minutes by 20 RPM. Qualitative and quantity analysis was made by FT-IR spectroscopy.
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Ceiling slab over the corner windows
Tuchyňová, Andrea ; Zich, Miloš (referee) ; Strnad, Jiří (advisor)
This bachelor thesis concerns design of reinforced concrete ceiling slab with girder above the corner windows. The slab has rectangular floor plan with large opening in the middle. The slab is dimensioned to the ultimate limit state and serviceability limit state. The inner forces on the bar model were assessed by force method and were compared with inner forces on spatial model created in Scia Engineering programme.
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Substitution of cellulose and non-edible collagen casings by plastic casings in the meat industry in the Czech Republic
BURIAN, Rudolf
The aim of this thesis is to assess the possibility of substitution of cellulose and non-edible collagen casings by plastic casings. The first part deals with selected types of casings, as well as their basic definitions, technological properties and applications, as described in literature. The second part describes the process of carrying out the analysis itself, from the selection of appropriate types of casings produced by Viscofan CZ Ltd. České Budějovice, through the measurement of their chosen technological properties, to the data evaluation
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Use of the extrusion process to produce biogas from wheat straw
VERNER, Dušan
Many agricultural biogas stations process predominantly phytomass specifically grown for power engineering purposes as a primary raw material. This results in gradual increase of maize proportion in sowing sequences at the exclusion of traditional area-specific crops, which presents various potential negative effects. The aim of study is to evaluate the substitution of maize with wheat straw in the anaerobic fermentation process from the biotechnological and economic viewpoint. For this purpose, wheat straw pellets were pretreated using the high-pressure extruder in compliance with UV CZ 21314 at different runtime parameters. Cumulative methane (CH4) production in quarter-mode operation simulation, based on the extrusion pressure, cycle duration and fermentation temperature, was the main evaluation criteria. Optimal run time parameters were derived from the approximation ? extrusion pressure 1,35 MPa, reaction time 210 s, in order to achieve maximal CH4 production at mesophilic fermentation temperature (38 °C). For fermentation temperature 48 °C, optimal pressure 1,25 MPa and cycle duration 180 s were approximated. The discount rate of Net Present Value (NPV) was established as a main comparative criterion considering overall executive, legislative and technological aspects of analyzed biological effects. Based on these findings suggest, wheat straw extrusion is interesting, unconventional and profitable technology in the field of biogas production.
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Technological and economic assessment of the use of extrusion of corn silage for biogas
MALÍK, Vladimír
My work assesses the technology use of corn silage extrusion for biogass production based on biological proces, technological limits, legislation and financial indicators of the biogass station. The theoretical part of the thesis is focused on the extrusion process. Based on the robust simulation of the experimental part we can conclude, that the pressure of 1.372 MPa probably moves close to the biotechnological optimum in the relation to the kinetics production of CH4 in certain conditions (the temperature of 38 °C, the delay time of the corn silage in the high pressure extruder CZ UV 21314 was 600 s). From the economic point of view, the assessment was carried out using the net present value (NPV), which serves as a criterion for evaluation of the profitability of investment projects. The technology seems to be a very interesting alternative not only for financial viability reasons, but also in relation to the environment.
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Fatigue crack initiation — the role of point defects
Polák, Jaroslav ; Man, Jiří
The role of point defects in the formation of surface relief and in the initiation of a fatigue crack in crystalline materials is analyzed. The dislocation interactions in the bands of intensive cyclic slip are specified and relations describing the formation and annihilation of interstitial and vacancy type defects are derived. The formation, annihilation and migration of point defects is proposed to be responsible for the mass redistribution within PSB and between PSB and the matrix boundary. The redistribution of the matter results in local tensile and compressive stresses that are relaxed by continuous dislocation movement within PSB and lead to the formation of characteristic surface relief in the form of extrusions and intrusions.
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