Thermal stress evaluation of thermo-blast jet nozzle materials / I.A. Gorlach

In the last few years a new method for surface preparation has evolved, namely thermo-abrasive blasting. This technique utilises a high enthalpy thermal jet to propel abrasive particles. The thermo-abrasive blasting gun, also called a thermal gun, is based on the principles of High Velocity Air Fuel...

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Main Author: Gorlach, Igor Alexandrowich
Published: North-West University 2009
Subjects:
Online Access:http://hdl.handle.net/10394/352
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spelling ndltd-NWUBOLOKA1-oai-dspace.nwu.ac.za-10394-3522014-04-16T03:54:56ZThermal stress evaluation of thermo-blast jet nozzle materials / I.A. GorlachGorlach, Igor AlexandrowichHVAFNozzleThermal stressesIn the last few years a new method for surface preparation has evolved, namely thermo-abrasive blasting. This technique utilises a high enthalpy thermal jet to propel abrasive particles. The thermo-abrasive blasting gun, also called a thermal gun, is based on the principles of High Velocity Air Fuel (HVAF) processes. Nozzles used for thermo-abrasive blasting are subjected to thermal loading, wear and mechanical stresses. Therefore, the nozzle geometry and materials are critical for reliable performance of a thermo-abrasive system. In this investigation, the thermal stresses developed in the nozzle materials for thermo-abrasive blasting were analysed. The analytical and the computational models of the thermo-abrasive gun and the nozzle were developed. The computational fluid dynamics, thermal and structural finite element analyses have been employed in this study. The nozzle materials investigated were tungsten carbide, hot pressed silicon carbide, nitride-bonded cast silicon carbide and SIALON. The simulation and experimental results show that the highest thermal stresses occur during the first two minutes from the start of the thermal gun. However, thermal stresses are also high after the system is shut off. The nozzle geometry was optimised, which provided high cleaning rates with evidence of improved thermal loading, based on the experimental results. A new design of the thermal gun and the ignition method associated with a HVAF system were developed in this study. It is also concluded that the computation fluid dynamic and the finite element technique can be used to optimise the design of thermo-abrasive blasting nozzles.Thesis (Ph.D. (Mechanical Engineering))--North-West University, Potchefstroom Campus, 2004.North-West University2009-02-04T09:22:57Z2009-02-04T09:22:57Z2004Thesishttp://hdl.handle.net/10394/352
collection NDLTD
sources NDLTD
topic HVAF
Nozzle
Thermal stresses
spellingShingle HVAF
Nozzle
Thermal stresses
Gorlach, Igor Alexandrowich
Thermal stress evaluation of thermo-blast jet nozzle materials / I.A. Gorlach
description In the last few years a new method for surface preparation has evolved, namely thermo-abrasive blasting. This technique utilises a high enthalpy thermal jet to propel abrasive particles. The thermo-abrasive blasting gun, also called a thermal gun, is based on the principles of High Velocity Air Fuel (HVAF) processes. Nozzles used for thermo-abrasive blasting are subjected to thermal loading, wear and mechanical stresses. Therefore, the nozzle geometry and materials are critical for reliable performance of a thermo-abrasive system. In this investigation, the thermal stresses developed in the nozzle materials for thermo-abrasive blasting were analysed. The analytical and the computational models of the thermo-abrasive gun and the nozzle were developed. The computational fluid dynamics, thermal and structural finite element analyses have been employed in this study. The nozzle materials investigated were tungsten carbide, hot pressed silicon carbide, nitride-bonded cast silicon carbide and SIALON. The simulation and experimental results show that the highest thermal stresses occur during the first two minutes from the start of the thermal gun. However, thermal stresses are also high after the system is shut off. The nozzle geometry was optimised, which provided high cleaning rates with evidence of improved thermal loading, based on the experimental results. A new design of the thermal gun and the ignition method associated with a HVAF system were developed in this study. It is also concluded that the computation fluid dynamic and the finite element technique can be used to optimise the design of thermo-abrasive blasting nozzles. === Thesis (Ph.D. (Mechanical Engineering))--North-West University, Potchefstroom Campus, 2004.
author Gorlach, Igor Alexandrowich
author_facet Gorlach, Igor Alexandrowich
author_sort Gorlach, Igor Alexandrowich
title Thermal stress evaluation of thermo-blast jet nozzle materials / I.A. Gorlach
title_short Thermal stress evaluation of thermo-blast jet nozzle materials / I.A. Gorlach
title_full Thermal stress evaluation of thermo-blast jet nozzle materials / I.A. Gorlach
title_fullStr Thermal stress evaluation of thermo-blast jet nozzle materials / I.A. Gorlach
title_full_unstemmed Thermal stress evaluation of thermo-blast jet nozzle materials / I.A. Gorlach
title_sort thermal stress evaluation of thermo-blast jet nozzle materials / i.a. gorlach
publisher North-West University
publishDate 2009
url http://hdl.handle.net/10394/352
work_keys_str_mv AT gorlachigoralexandrowich thermalstressevaluationofthermoblastjetnozzlematerialsiagorlach
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