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Number of results: 4
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Abstract

The physical properties determining the strength parameters of bituminous mixtures are strongly influenced by the processes of placement and compaction. The effectiveness of this process depends on the compactive effort and is directly related to the mixture temperature. This research focused on the assessment of compactibility of mixtures designed for reflective crack relief interlayers (RCRI) which, in most cases, are applied in thin layers. The materials analysed for compactibility in this research included AC – asphalt concrete, AC AF – asphalt concrete “anti-fatigue”, SMA – stone mastic asphalt and SMA-MA – stone mastic asphalt rich in bitumen mastic. The gyratory compactor method was used to determine the compaction slope K, the locking point LP and the compaction densification index CDI. All the tested mixtures were fine-graded, i.e., contained grains up to 8 mm in diameter, each mixed with a different type of bituminous binder. The values of CDI show a substantially greater input of energy required for compaction of high-polymer modified mixtures, as compared to mixtures of the same design, yet containing the 50/70 bitumen. Locking point analysis showed that SMA and SMA-MA mixtures attain 98% relative compaction before reaching the locking point at which the aggregate skeleton starts to resist further compaction. This is quite the opposite as with the AC and AC AF mixtures. Among the tested mixtures the best compaction behaviour was observed in the case of SMA-MA 8 50/70, and this over a wide range of working temperature (100–160C°) and pressures (150 kPa, 600 kPa). The design of the mixture SMA-MA as an anti-fatigue layer assumes an increase in the content of filler and binder, as compared to conventional SMA. This composition is bound to reduce the resistance to compaction, i.e., provide a better compaction behaviour as compared to a conventional SMA mixture.
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Authors and Affiliations

Oliwia Merska
1
ORCID: ORCID
Paweł Mieczkowski
1
ORCID: ORCID
Stanisław Majer
1
ORCID: ORCID

  1. West Pomeranian University of Technology, Faculty of Civil and Engineering, ul. Piastów 50A, 70-333 Szczecin, Poland
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Abstract

This paper proposes a mathematical model that allows expanding the scope of research into the mechanism of heat transfer during explosive boiling, cavitation and boiling of multicomponent liquids, identifying the most influential factors and optimizing technological processes. The proposed model takes into account the processes of heat accumulation in the high-boiling part of liquid mixtures (for example, emulsions) and the use of this energy in the process of boiling their thermolabile part, as well as for superheating the resulting steam in steam bubbles. This effect can also be used to evaluate the effects of liquid boiling in thermodynamically unstable regions of liquid media.
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Authors and Affiliations

Hanna Koshlak
1

  1. Kielce University of Technology, Department of Sanitary Engineering,Aleja Tysiąclecia Państwa Polskiego 7, 25-314, Kielce, Poland
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Abstract

This paper deals with the numerical simulation of a pilot-scale axial cyclone separator. The main purpose of this paper is to develop a numerical model that is able to foresee the cyclone separator cut-off point. This is crucial in blast furnace gas installation to capture large particles containing carbon and iron, while allowing smaller particles such as zinc and lead to pass through. The cut-off point must be designed to give a sufficiently high zinc and lead content in the sludge created after the second cleaning stage. This allows the sludge to become a commercial product. To design this cut-off point, an investigation of the influence of inlet gas velocity, temperature, and the angle of guiding vanes at the inlet was done. The developed CFD model was validated against experimental data on the fractional efficiency of the cyclone separator. The results were in good agreement with the experimental data for all parameters tested. The behavior of the particles inside the cyclone was also physically correct.
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Authors and Affiliations

Arkadiusz Ryfa
1
Mieszko Tokarski
2
Wojciech Adamczyk
1
Adam Klimanek
1
Paweł Bargiel
1
Ryszard Białecki
1
Michał Kocot
3
Harald Kania
4
Janusz Stecko
4
Marianna Czaplicka
5
ORCID: ORCID

  1. Silesian University of Technology, Institute of Thermal Technology, Konarskiego 22, 44-100 Gliwice, Poland
  2. Silesian University of Technology, Institute of Thermal Technology, Konarskiego 22, 44-100 Gliwice, Poland; AGH University of Science and Technology, Department of Fuels Technology, Czarnowiejska 30, 30-059, Kraków, Poland
  3. ArcelorMittal Poland, al. Piłsudskiego 92, 41-308 Dąbrowa Górnicza, PolandNiesler, Marian : Institute for Ferrous Metallurgy, Łukasiewicz Research Network, Karola Miarki 12, 44-100 Gliwice, Poland
  4. Institute for Ferrous Metallurgy, Łukasiewicz Research Network, Karola Miarki 12, 44-100 Gliwice, Poland
  5. Institute of Environmental Engineering, Polish Academy of Sciences, Marii Skłodowskiej-Curie 34, 41-819 Zabrze, Poland
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Abstract

Poland is a significant producer of vegetable sprouts, which, due to the high content of nutrients, are produced for food purposes. The cultivation cycle of these plants, especially the mung beans (Vigna radiata), is associated with significant exploitation of natural resources (as much as 275 dm3 of water per 1 kg of dry seeds) and requires appropriate temperature conditions. However, since producing of vegetable sprouts is an exothermic process, there are reasons to organize the growth conditions of these plants in a quasi-autonomous manner. Estimated preliminary studies show that during the entire period of sprout growth, as much as 2.86 MJ of heat from 1 kg of dry seeds can be used, which, taking into account the scale of production of these plants, places them among the significant sources of low-temperature waste heat. The paper presents the results of temperature measurements carried out in a growth chamber used for the industrial production of the mung bean vegetable sprouts. Based on the prepared energy balance, the total amount of heat generated (4.9 GJ) and recovered (3.3 GJ) in the seed germination process was determined. The amount of energy lost in the process of imbibition and the amount of heat needed to ensure optimal plant growth conditions were determined. The study shows that the use of low-temperature heat generated by plants allows for a significant reduction in the energy consumption of the production process.
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Authors and Affiliations

Paweł Mirek
1
Marcin Panowski
1
Klaudia Słomczyńska
2
Michał Stanek
3
Tomasz Bąkowski
3

  1. Czestochowa University of Technology, Faculty of Infrastructure and Environment, Dąbrowskiego 69, 42-201 Częstochowa, Poland
  2. Czestochowa University of Technology, Faculty of Infrastructure and Environment, Dąbrowskiego 69, 42-201 Częstochowa, Poland; ENERGOPROJEKT-KATOWICE SA, Jesionowa 15, 40-159 Katowice, Poland
  3. Uniflora Sp. z o.o., Lwowska 8, 42-202 Częstochowa, Poland

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