3/2016
• 3/2016 table of contents
Bodnár István, Plásztán Bence
Thermokinetic modelling of wood biomass pyrolysis 5
The optimal parameters of the Pyrolysis Technology have been investigated. During the thermokinetic modelling of the procedure pyrolysis of different chemical combination biomasses have been analysed. The modelling has been executed at different wood biomass, and in different percentages of moisture. On the basis of the wood’s chemical composition and of the reaction equation We have made an approximate model, which helps to specify the resulting pyrolysis gas’ chemical composition and the energetic properties. The results have been compared with the required reaction efficiency and with the energy generation.
Dr. Farkas József, Dr. Jármai Károly
Optimum design of the main girder of overhead travelling crane 13
The paper shows the optimum design of the main girder of an overhead travelling crane, made of welded box beam. The objective function is the cost of the structure, which contains the material and the welding costs. The unknowns are the dimensions of the box beam. The constraints are the static and fatigue stresses, the local stability of the webs and flanges. It is shown, that using post welding treatment, one can improve the behaviour of the fatigue girder, with and acceptable cost. It is also shown, that the cost and mass minima are different.
Dr. Jármai Károly, Dr. Kota László
Introduction to the Open Journal Systems 18
The paper contains an introduction to the Open Journal Systems (OJS, https://pkp.sfu.ca/ojs/). OJS is a journal man-agement and publishing system that has been developed by the Public Knowledge Project through its federally funded efforts to expand and improve access to research. OJS is open source software made freely available to journals worldwide for the purpose of making open access publish-ing a viable option for more journals, as open access can increase a journal’s readership. We have installed and used OJS for the Journal GÉP.
Petrik Máté, Dr. Szepesi L. Gábor, Dr. Jármai Károly
Optimal design of shell-and-tube heat exchangers 23
Heat exchangers are one of the most common used equipment in the industry and in the households. This heat transfer device exchanges heat between two or more process fluids. In a specific project, we can use many types of heat exchangers, like air coolers, shell-and-tube or plate heat exchangers and graphite block heat exchangers. In case of optimal design, we would like to choose the cheapest construction, which is able to transfer the necessary heat. In my project I deal with especially the shell-and-tube heat exchangers optimal design. The results are calculated by the Excel Solver application.
Sebe István, Száva Ildikó Renáta, Dr. Jármai Károly
Optimum design of vessel supporting frame for fire 28
This article deals with the optimization of a vessel supporting frame for fire. A structure is economical, if its mass is the smallest as possible.
Mass optimizations without fire and with fire are discussed. Nowadays a lot of fire protection solutions are available, increase of the mass of steel and using higher yield stress steel are presented. In the next phase of this project we will deal with other methods and their costs, for example intumescent coating, vermiculite or fire protection gypsum boards.
Spisák Bernadett, Dr. Siménfalvi Zoltán Károly, Dr. Szepesi Gábor
Testing and simulation of spring loaded safety relief valve 34
In every chemical industry practice the pressure systems take a very important role. In order to these devices work well accurate planning and technologically correct production is required, but there can be mistakes during operation. We need to take precautionary measures against these hazards. In the pressure systems the safety relief valves fill this job. Current article should introduce the magnitude of the buoyant force on a safety relief valve in experiment and simulation.
Varga Tibor, Dr. Szepesi L. Gábor, Dr. Siménfalvi Zoltán
Primary and secondary flow inside the horizontal scraped surface heat exchanger for different internal constructions 37
The difficulties of thermal treatment of specific, high viscous, sensitive products in chemical, food and consumption industry is caused by presence of intensive fouling on heat transfer surface. Therefore those products are thermally processed in scraped surface heat exchangers. The research of these type of heat exchangers has already a long background. The obtained results give evidence about the benefits and some possible disadvantages of these type of internal constructions and about their favourable process conditions. Based on the result additional changes can be applied on the internal constructions to improve some flow characteristic issues.
Dr. Virág Zoltán, Dr. Jármai Károly
Effects of material quality and span length on the optimum design of non-standard sized above-ground pipelines 45
The optimum design is widely used in engineering practice. It is always important to aim at the best price or just material saving. The optimum dimensions of the pipeline can be determined using different steel grades, span lengths and different geometrical and loading conditions. Span length, material quality, tube diameter and thickness are variables. In this study only the material cost is minimised.
Zsemberi Andor, Dr. Siménfalvi Zoltán Károly, Dr. Palotás Árpád Bence
Thermal and thermo catalytic co-cracking 49
The catalytic co-cracking of biomass, polymer waste, or brown coal could be an economical process for production of high value added aromatics components, which are obtained from crude oil currently. In this study thermal and thermo-catalytic cracking of polystyrene waste was carried out to produce aromatic hydrocarbons. A synergistic effect between the coated metal mesh and the melted polymer was observed, that promoted the production of liquid aromatics fraction significantly.
Bodnár István, Plásztán Bence
Thermokinetic modelling of wood biomass pyrolysis 5
The optimal parameters of the Pyrolysis Technology have been investigated. During the thermokinetic modelling of the procedure pyrolysis of different chemical combination biomasses have been analysed. The modelling has been executed at different wood biomass, and in different percentages of moisture. On the basis of the wood’s chemical composition and of the reaction equation We have made an approximate model, which helps to specify the resulting pyrolysis gas’ chemical composition and the energetic properties. The results have been compared with the required reaction efficiency and with the energy generation.
Dr. Farkas József, Dr. Jármai Károly
Optimum design of the main girder of overhead travelling crane 13
The paper shows the optimum design of the main girder of an overhead travelling crane, made of welded box beam. The objective function is the cost of the structure, which contains the material and the welding costs. The unknowns are the dimensions of the box beam. The constraints are the static and fatigue stresses, the local stability of the webs and flanges. It is shown, that using post welding treatment, one can improve the behaviour of the fatigue girder, with and acceptable cost. It is also shown, that the cost and mass minima are different.
Dr. Jármai Károly, Dr. Kota László
Introduction to the Open Journal Systems 18
The paper contains an introduction to the Open Journal Systems (OJS, https://pkp.sfu.ca/ojs/). OJS is a journal man-agement and publishing system that has been developed by the Public Knowledge Project through its federally funded efforts to expand and improve access to research. OJS is open source software made freely available to journals worldwide for the purpose of making open access publish-ing a viable option for more journals, as open access can increase a journal’s readership. We have installed and used OJS for the Journal GÉP.
Petrik Máté, Dr. Szepesi L. Gábor, Dr. Jármai Károly
Optimal design of shell-and-tube heat exchangers 23
Heat exchangers are one of the most common used equipment in the industry and in the households. This heat transfer device exchanges heat between two or more process fluids. In a specific project, we can use many types of heat exchangers, like air coolers, shell-and-tube or plate heat exchangers and graphite block heat exchangers. In case of optimal design, we would like to choose the cheapest construction, which is able to transfer the necessary heat. In my project I deal with especially the shell-and-tube heat exchangers optimal design. The results are calculated by the Excel Solver application.
Sebe István, Száva Ildikó Renáta, Dr. Jármai Károly
Optimum design of vessel supporting frame for fire 28
This article deals with the optimization of a vessel supporting frame for fire. A structure is economical, if its mass is the smallest as possible.
Mass optimizations without fire and with fire are discussed. Nowadays a lot of fire protection solutions are available, increase of the mass of steel and using higher yield stress steel are presented. In the next phase of this project we will deal with other methods and their costs, for example intumescent coating, vermiculite or fire protection gypsum boards.
Spisák Bernadett, Dr. Siménfalvi Zoltán Károly, Dr. Szepesi Gábor
Testing and simulation of spring loaded safety relief valve 34
In every chemical industry practice the pressure systems take a very important role. In order to these devices work well accurate planning and technologically correct production is required, but there can be mistakes during operation. We need to take precautionary measures against these hazards. In the pressure systems the safety relief valves fill this job. Current article should introduce the magnitude of the buoyant force on a safety relief valve in experiment and simulation.
Varga Tibor, Dr. Szepesi L. Gábor, Dr. Siménfalvi Zoltán
Primary and secondary flow inside the horizontal scraped surface heat exchanger for different internal constructions 37
The difficulties of thermal treatment of specific, high viscous, sensitive products in chemical, food and consumption industry is caused by presence of intensive fouling on heat transfer surface. Therefore those products are thermally processed in scraped surface heat exchangers. The research of these type of heat exchangers has already a long background. The obtained results give evidence about the benefits and some possible disadvantages of these type of internal constructions and about their favourable process conditions. Based on the result additional changes can be applied on the internal constructions to improve some flow characteristic issues.
Dr. Virág Zoltán, Dr. Jármai Károly
Effects of material quality and span length on the optimum design of non-standard sized above-ground pipelines 45
The optimum design is widely used in engineering practice. It is always important to aim at the best price or just material saving. The optimum dimensions of the pipeline can be determined using different steel grades, span lengths and different geometrical and loading conditions. Span length, material quality, tube diameter and thickness are variables. In this study only the material cost is minimised.
Zsemberi Andor, Dr. Siménfalvi Zoltán Károly, Dr. Palotás Árpád Bence
Thermal and thermo catalytic co-cracking 49
The catalytic co-cracking of biomass, polymer waste, or brown coal could be an economical process for production of high value added aromatics components, which are obtained from crude oil currently. In this study thermal and thermo-catalytic cracking of polystyrene waste was carried out to produce aromatic hydrocarbons. A synergistic effect between the coated metal mesh and the melted polymer was observed, that promoted the production of liquid aromatics fraction significantly.
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