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Testing of Nozzles
Foldyna, Josef ; Sitek, Libor ; Ščučka, Jiří ; Klich, Jiří ; Hlaváček, Petr
Based on the request made by the company NET Ltd. Staré Město pod Sněžníkem, tests of quality of nozzles for generation of high-speed water jet were performed at the Department of material disintegration of the Institute of Geonics AS CR, v. v. i., in Ostrava. Three nozzles provided by NET were tested. The nozzles were marked as nozzle CKM – A, nozzle CKM – B, and nozzle ACMK. The nozzle quality was evaluated by the determination of their discharge coefficient at various operating pressures and by visual inspection of the quality of the nozzle and the water jet.
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New possibilities in the area of using of water jet technology for the removal of concrete surface layers
Bodnárová, L. ; Hela, R. ; Foldyna, Josef ; Sitek, Libor
The contribution deals with problems of using of water jet technology for the removal of concrete surface layers. Realized experimental tests were focused on the possibility of using of water jet technology in the stage of concrete surface preparation for the repair of concrete structures. The contribution specifies some new possibilities in the use of water jet technology for the concrete disintegration. The circumstances of surface layers removal through various types of water jet were investigated on concrete samples with different characteristics of surface layers. In the paper, possibilities of high-speed water jet technology are extended to the application of so-called flat water jet. Interesting results in relatively low energy demands can be achieved during disintegration of very hard concrete in conjunction with an acoustic pulse generator.
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Water Jet 2009. Proceedings
Sitek, Libor
Conference Water Jet 2009 - Research, Development, Application, which is organized by the Department of material disintegration of the Institute of Geonics of the ASCR, v. v. i., is the first meeting of producers, users, designers and other people interested in technology of high speed water jet in the Czech Republic. The main objective of the conference is to provide forum for exchange of knowledge, information and experiences in areas of research, development and application of water jet. Although the conference was originally intended as a more or less local meeting of experts from the Czech Republic, a number of foreign participants proves that this issue is very attractive far beyond the borders of the CR. Problems solved in contributions are very diverse: they range from basic research through traditional and less traditional application of technology in practice to reflection on the impact of the current economic crisis on job shops.
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Turning by high-speed abrasive water jet – our experiences
Sitek, Libor
The paper describes and analyses our own experiences concerning technology of turning by high speed abrasive water jet. Technology development as well as present stay-of–the-art in given area are introduced in brief. Possibilities of application of such machining method especially for shaping and preparation of testing rock specimens suitable for determination of physical-mechanical properties of rocks are also discussed.
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Comparison of Continuous High-Pressure Generated and Pulsing Low-Pressure Generated Water Jets on Concrete
Mádr, V. ; Sitek, Libor ; Hela, R. ; Hlaváč, L. M. ; Bodnárová, L. ; Pustelník, J. ; Janurová, E.
The concrete samples with various erosion states were disintegrated by pure continuous water jets generated from pressure 380 MPa in the Liquid jet laboratory at the VŠB - Technical University of Ostrava. Simultaneously, the identical concrete samples were tested by pulsing water jets generated by low pressure 30 MPa in the Department of Material Disintegration at the Institute of Geonics of the AS CR. The erosion states of samples were prepared by application of several laboratory techniques simulating the concrete aging under the natural conditions due to the real applications in practice. They were prepared at the 127 Institute of Technology of Building Materials and Components of the Brno University of Technology. The influence of the erosion state on the disintegration rate was tested and the surface topography was studied. The comparison of both the depth of penetration and the volume disintegration ratio regarding the input power is performed.
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