How to search?
advanced search

Search results

Filters

  • Journals
  • Authors
  • Keywords
  • Date
  • Type

Search results

Number of results: 6
items per page: 25 50 75
Sort by:

Studies on the process of recovering low-temperature waste heat from a flue gas in a pilot-scale plant

Piotr Szulc Kazimierz Wójs Tomasz Tietze
Chemical and Process Engineering | 2016 | vol. 37 | No 4 December | 529-543 | DOI: 10.1515/cpe-2016-0043
Keywords heat recovery condensation inert gas
Download PDF Download RIS Download Bibtex

Abstract

This paper presents studies carried out in a pilot-scale plant for recovery of waste heat from a flue gas which has been built in a lignite-fired power plant. The purpose of the studies was to check the operation of the heat recovery system in a pilot scale, while the purpose of the plant was recovery of waste heat from the flue gas in the form of hot water with a temperature of approx. 90 °C. The main part of the test rig was a condensing heat exchanger designed and built on the basis of laboratory tests conducted by the authors of this paper. Tests conducted on the pilot-scale plant concerned the thermal and flow parameters of the condensing heat exchanger as well as the impact of the volumetric flow rate of the flue gas and the cooling water on the heat flux recovered. Results show that the system with a condensing heat exchanger for recovery of low-temperature waste heat from the flue gas enables the recovery of much higher heat flux as compared with conventional systems without a condensing heat exchanger.

Go to article

Authors and Affiliations

Piotr Szulc
Kazimierz Wójs
Tomasz Tietze

Physical Modelling of Degassing Process by Blowing of Inert Gas

M. Tkadlečková K. Gryc K. Michalek L. Socha M. Saternus T. Merder J. Pieprzyca
Archives of Metallurgy and Materials | 2018 | vol. 63 | No 2 | DOI: 10.24425/122432
Keywords physical modelling refining ladle inert gas blowing degassing process impeller
Download PDF Download RIS Download Bibtex

Abstract

This paper deals with the possibilities of using physical modelling to study the degassing of metal melt during its treatment in the refining ladle. The method of inert gas blowing, so-called refining gas, presents the most common operational technology for the elimination of impurities from molten metal, e.g. for decreasing or removing the hydrogen content from liquid aluminium. This refining process presents the system of gas-liquid and its efficiency depends on the creation of fine bubbles with a high interphase surface, uniform distribution, long period of its effect in the melt, and mostly on the uniform arrangement of bubbles into the whole volume of the refining ladle. Physical modelling represents the basic method of modelling and it makes it possible to obtain information about the course of refining processes. On the basis of obtained results, it is possible to predict the behaviour of the real system during different changes in the process. The experimental part focuses on the evaluation of methodical laboratory experiments aimed at the proposal and testing of the developed methods of degassing during physical modelling. The results obtained on the basis of laboratory experiments realized on the specific physical model were discussed.
Go to article

Authors and Affiliations

M. Tkadlečková
K. Gryc
K. Michalek
L. Socha
M. Saternus
T. Merder
J. Pieprzyca

The Influence of Optimization Parameters on the Efficiency of Aluminium Melt Refining by using Physical Modelling

J. Walek K. Michalek M. Tkadlečková
Archives of Foundry Engineering | 2022 | vol. 22 | No 3 | 60-66 | DOI: 10.24425/afe.2022.140237
Keywords physical modelling Refining ladle Blowing of inert gas Degassing of the melt Impeller
Download PDF Download RIS Download Bibtex

Abstract

The article describes the influence of optimization parameters on the efficiency of aluminium melt refining by using physical modelling. The blowing of refining gas, through a rotating impeller into the ladle is a widely used operating technology to reduce the content of impurities in molten aluminium, e.g. hydrogen. The efficiency of this refining process depends on the creation of fine bubbles with a high interphase surface, wide-spread distribution, the residence time of its effect in the melt, and mostly on the wide-spread dispersion of bubbles in the whole volume of the refining ladle and with the long period of their effect in the melt. For physical modelling, a plexiglass model on a scale of 1:1 is used for the operating ladle. Part of the physical model is a hollow shaft used for gas supply equipped with an impeller and also two baffles. The basis of physical modelling consists in the targeted utilization of the similarities of the processes that take place within the actual device and its model. The degassing process of aluminium melt by blowing inert gas is simulated in physical modelling by a decrease of dissolved oxygen in the model liquid (water).
Go to article

Bibliography

[1] Michalek, K., Tkadlečková, M., Socha, L., Gryc, K., Saternus, M., Pieprzyca, J. & Merder, T. (2018). Physical modelling of degassing process by blowing of inert gas. Archives of Metallurgy and Materials. 63(2), 987-992. DOI: 10.24425/122432.
[2] Hernández-Hernández, M., Camacho-Martínez, J., González-Rivera, C. & Ramírez-Argáez, M.A. (2016). Impeller design assisted by physical modelling and pilot plant trials. Journal of Materials Processing Technology. 236, 1-8. DOI: 10.1016/j.jmatprotec.2016.04.031.
[3] Mostafei, M., Ghodabi, M., Eisaabadi, G.B., Uludag, M. & Tiryakioglu, M. (2016). Evaluation of the effects rotary degassing process variables on the quality of A357 aluminium alloy castings. Metallurgical and Materials Transactions B. 47(6), 3469-3475. DOI: 10.1017/s11663-016-0786-7.
[4] Merder, T., Saternus, M. & Warzecha, P. (2014). Possibilities of 3D Model application in the process of aluminium refining in the unit with rotary impeller. Archives of Metallurgy and Materials. 59(2), 789-794. DOI: 10.2478/amm-2014-0134.
[5] Saternus, M., Merder, T. & Pieprzyca, J. (2015). The influence of impeller geometry on the gas bubbles dispersion in URO-200 reactor – RTD curves. Archives of Metallurgy and Materials. 60(4), 2887-2893. DOI: 10.1515/amm-2015-0461.
[6] Yamamoto, T., Suzuki, A., Komarov, S.V. & Ishiwata, Y. (2018). Investigation of impeller design and flow structures in mechanical stirring of molten aluminium. Journal of Materials Processing Technology. 261, 164-172. DOI: 10.1016/j.jmatprotec.2018.06.012.
[7] Gao, G., Wang, M., Shi, D. & Kang, Y. (2019). Simulation of bubble behavior in a water physical model of an aluminium degassing ladle unit employing compound technique of rotary blowing and ultrasonic. Metallurgical and Materials Transactions B. 50(4), 1997-2005. DOI: 10.1017/j.s11663-019-01607-y. [8] Yu, S., Zou, Z.-S., Shao, L. & Louhenkilpi, S. (2017). A theoretical scaling equation for designing physical modelling of gas-liquid flow in metallurgical ladles. Steel Research International. 88(1), 1600156. DOI: 10.1002/srin.201600156.
[9] Abreu-López, D., Dutta, A., Camacho-Martínez, J.L., Trápaga-Martínez, G. & Ramírez-Argáez, M. A. (2018). Mass transfer study of a batch aluminium degassing ladle with multiple designs of rotating impellers. JOM. 70, 2958-2967. DOI: 10.1007/s11837-018-3147-y.
[10] Walek, J., Michalek, K., Tkadlečková, M. & Saternus, M. (2021). Modelling of technological parameters of aluminium melt refining in the ladle by blowing of inert gas through the rotating impeller. Metals. 11(2), 284. DOI: 10.3390/met11020284.
[11] Saternus, M. & Merder, T. (2018). Physical modelling of aluminium refining process conducted in batch reactor with rotary impeller. Metals. 8(9), 726. DOI: 10.3390/met8090726.
[12] Lichý, P., Bajerová, M., Kroupová, I. & Obzina, T. (2020). Refining aluminium-alloy melts with graphite rotors. Materiali in Technologije. 54(2), 263-265. DOI: 10.17222/mit.2019.147.
[13] Lichý, P., Kroupová, I., Radkovský, F. & Nguyenová, I. (2016). Possibilities of the controlled gasification of aluminium alloys for eliminating the casting defects. 25th Anniversary International Conference on Metallurgy and Materials, May 25th - 27th 2016 (1474-1479). Hotel Voroněž I, Brno, Czech Republic, EU: Lichý, P.

Go to article

Authors and Affiliations

J. Walek
1
ORCID: ORCID
K. Michalek
1
ORCID: ORCID
M. Tkadlečková
1
ORCID: ORCID
  1. VŠB - Technical University of Ostrava, Faculty of Materials Science and Technology, Department of Metallurgical Technologies

Analysis of chosen aspects of a tank gassing-up process on board liquefied petroleum gas carrier. Part II

Agnieszka Wieczorek
Archives of Thermodynamics | 2021 | vol. 42 | No 2 | 59-69 | DOI: 10.24425/ather.2021.137553
Keywords Filling the tank Gassing-up Ideal gas Gas mixing Ethylene Nitrogen Inert gas Cargo vapour
Download PDF Download RIS Download Bibtex

Abstract

The paper presents a thermodynamic analysis of the removal of an inert gas from the tank using the vapor of liquefied petroleum gas cargo (called cargo tank gassing-up operation). For this purpose a thermodynamic model was created which considers two extreme cases of this process. The first is ‘piston pushing’ of inert gas using liquefied petroleum gas vapour. The second case is the complete mixing of both gases and removal the mixture from the tank to the atmosphere until desired concentration or amount of liquefied petroleum gas cargo in the tank is reached. On the example of nitrogen as inert gas and ethylene as a cargo, by thermodynamic analysis an attempt was made to determine the technical parameters of the process, i.e., pressure in the tank, temperature, time at which the operation would be carried out in an optimal way, minimizing the loss of cargo used for gassingup. Calculations made it possible to determine the amount of ethylene used to complete the operation and its loss incurred as a result of total mixing of both gases.
Go to article

Authors and Affiliations

Agnieszka Wieczorek
1
  1. Gdynia Maritime University, Morska 81–87, 81-225 Gdynia, Poland

Optimization of GTAW Process Parameters of Dissimilar Al-Mg Alloys for Enhanced Joint Strength – Taguchi Approach

D. Antony Prabu K.S. Jayakumar E. Madhavan Pillai G. Kumaresan
Archives of Metallurgy and Materials | 2023 | vol. 68 | No 2 | 599-606 | DOI: 10.24425/amm.2023.142440
Keywords AA5052-H32 AA5083-H111 mechanical properties microstructures optimization Tungsten Inert gas welding
Download PDF Download RIS Download Bibtex

Abstract

The Tungsten Inert Gas (TIG) welding processes one of the prevalent methods used for welding aluminum alloys. TIG welding is most commonly used due to its superiority in welding less dense materials. The most prevalent issues encountered with TIG welding aluminium alloys are porosity creation and cracking due to solidification, both of which result in lower mechanical properties. Because of the metal’s susceptibility to heat input, this occurs. The current work is the result of a desire to improve the mechanical properties of dissimilar aluminium metals: AA5052-H32 & AA5083-H111. The process parameters of TIG welding are optimized towards eliminating the previously discussed failure scenarios. Various optimization techniques exist towards obtaining optimizing processes such as Response Surface Methodology (RSM), Genetic Algorithm (GA), Artificial Neutral Network (ANN), Flower pollination algorithm, Taguchi method etc, The Taguchi method was chosen for the optimization of process parameters due to its inherent nature of solving problems of singular variance. The optimal parameters combination was determined i.e. welding current at 170 A, filler rod diameter 2.4 mm and Gas flow rate of 11 lpm. The optimized input parameter was used to TIG weld the confirmation specimen which are further investigated for mechanical and metallurgical characterizations. The parameters were optimized and the results indicate that the input current was found to be the most contributing towards improving mechanical properties over all the process parameters.
Go to article

Authors and Affiliations

D. Antony Prabu
1
ORCID: ORCID
K.S. Jayakumar
2
ORCID: ORCID
E. Madhavan Pillai
1
ORCID: ORCID
G. Kumaresan
3
ORCID: ORCID
  1. LOYOLA-ICAM College of Engineering and Technology (LICET), Department of Mechanical Engineering, Loyola Campus, Chennai, Tamil Nadu, India
  2. Sri Sivasubramaniya Nadar College of Engineering, Department of Mechanical Engineering, Chennai, Tamil Nadu, India
  3. Bannari Amman Institute of Technology, Department of Mechanical Engineering, Sathyamangalam, Erode, Tamil Nadu, India

Analysis of heat flow in a tube bank of a condenser considering the influence of air

Magda Joachimiak Damian Joachimiak Piotr Krzyślak
Archives of Thermodynamics | 2017 | No 3 | 119-134 | DOI: 10.1515/aoter-2017-0019
Keywords condensation inert gas mass share of gas noncondensing in water vapor Dalton’s law water vapor pressure air partial pressure
Download PDF Download RIS Download Bibtex

Abstract

The pressure of wet water vapor inside a condenser has a great impact on the efficiency of thermal cycle. The value of this pressure depends on the mass share of inert gases (air). The knowledge of the spots where the air accumulates allows its effective extraction from the condenser, thus improving the conditions of condensation. The condensation of water vapor with the share of inert gas in a model tube bank of a condenser has been analyzed in this paper. The models include a static pressure loss of the water vapor/air mixture and the resultant changes in the water vapor parameters. The mass share of air in water vapor was calculated using the Dalton’s law. The model includes changes of flow and thermodynamic parameters based on the partial pressure of water vapor utilizing programmed water vapor tables. In the description of the conditions of condensation the Nusselts theory was applied. The model allows for a deterioration of the heat flow conditions resulting from the presence of air. The paper contains calculations of the water vapor flow with the initial mass share of air in the range 0.2 to 1%. The results of calculations clearly show a great impact of the share of air on the flow conditions and the deterioration of the conditions of condensation. The data obtained through the model for a given air/water vapor mixture velocity upstream of the tube bank allow for identification of the spots where the air accumulates.

Go to article

Authors and Affiliations

Magda Joachimiak
Damian Joachimiak
Piotr Krzyślak

This page uses 'cookies'. Learn more