Publications - Ventzas Dimitrios MODELING the TRANSIENT BUBBLING MECHANISM of a FLUIDIZED BED COMBUSTOR, D.E. Ventzas, P. Tsiakaras, International Conference on Contribution of Cognition to Modeling, CCM ’98, Lyon-France 01/02/2009   ABSTRACT: The fluidized bed modeling and control is investigated, focusing in fluidized bed combustors. The two phase Davidson’s flow model is limited, since it considers constant bubble size and rising velocity. Recent research work in two and three dimensional (atmospheric,circulating and pressurized) fluidized beds concluded that the intrinsic transient motion of gas bubbles in freely bubbling fluidized beds, contains multiple mechanisms for both fluidization, combustion and erosion processes, such as, bubble size changes, interaction, bubbles velocity, normal and abnormal fluidization condition, wall effect on fluidization, etc. The background average function of bubbles signal corresponds to the emulsion phase density.   More Information> INTELLIGENT VALVE CONTROL, D. E. Ventzas, C. Anagnostou, 3rd INTERNATIONAL CONFERENCE on INDUSTRIAL AUTOMATION, 7-9 June, 1999, Montreal, Canada 01/02/2009   Abstract: A flow valve is an integral part of any process loop; it is usually accompanied by an accurate sensor (a flowmeter) giving an additional tool in treating valve with modern AI tools by integrating some intelligent features. The control valve and its flow characteristic must fit the process, while the actuator must operate reliably. In conventional process flow loops this is an unquestioned matter after installation, but with AI this is continuously tested.   More Information> 3-ΔΙΑΣΤΑΤΑ ΕΡΓΑΛΕΙΑ για ΡΟΟΜΕΤΡΑ ΕΤΕΡΟΣΥΣΧΕΤΙΣΗΣ, Μετρολογία 2007, Θεσσαλονίκη 01/02/2009   Περίληψη: Η εργασία παρουσιάζει σύγχρονες εξελίξεις στην έρευνα μετρητών ροής με αλληλοσυσχέτιση, λόγω των εξελίξεων τόσο στον τομέα της επεξεργασίας σήματος όσο και στην κατανόηση των καθεστώτων ροής, με αποτέλεσμα καλύτερη επαναληπτικότητα της αλληλοσυσχέτισης. Αναπτύσσουμε, εφαρμόζουμε, χρησιμοποιούμε και ελέγχουμε 2& 3-διάστατα εργαλεία για τον σχεδιασμό, ανάπτυξη και έλεγχο ροομέτρων αλληλοσυσχέτισης. Οι αλληλοσυσχετίσεις στο χώρο-χρόνο συνάγονται από αποσβενύμενα ίχνη με ανεξάρτητες και τυχαίες εξετάσεις. Ο χρόνος μετάβασης της αλληλοσυσχέτισης εξαρτάται από την δομή και τις ιδιότητές ροής των ιχνών, και την απόσταση και ιδιότητες φίλτρων των αισθητήρων στο χώρο-χρόνο.   More Information> Crane Load Swing Suppression Control, WSEAS TRANSACTIONS on SYSTEMS, D. E. Ventzas, C. Pandazaras, Issue 3, Volume 5, March 2006, ISSN 1109-2777, http://www.wseas.org , p. 631 23/01/2009     The paper examines problems of an anti-sway system for crane control. The crane is modelled and simulated;anti-sway control results are presented and suggestions for further work are made.   http://www.wseas.org ...   More Information> Non-destructive testing of rotating equipment : Ventzas, D.E. Proceedings of the 4th European Conference on NDT, London, UK, 13–17 Sep. 1987. Vol. 2, pp. 1124–1131. Pergamon Press, 3173 pp. (1988) 18/01/2009   Abstract: this paper presents the practical aspects of the signal analysis in the field of acoustics and vibrations for rotating equipment NDT. Pulsation Study of Compressors - Signal Analysis for Industrial Compressor Robust Control under Pulsation Conditions 18/01/2009   Abstract: this paper describes the results of the pulsations study of the piping of refinery compressors. in the original piping the pulsations exceed the allowable level at all loading conditions. orifice plates at the damper line connection and in the cylinder connection of the discharge damper are recommended. besides it is recommended to increase the diameter of the cylinder connection of the discharge damper to reduce the pulsations near the compressor valves. with the recommended modifications the pulsations are within or slightly exceed the allowable level. the pulsation induced vibration forces on the most important pipe sections are also given. these data can be used for the design of the pipe clamping.   More Information> Binarization of pre-filtered historical manuscripts images, International Journal of Intelligent Computing and Cybernetics, IJICC, Emerald Group Publishing Limited, issue 1, March 2009 18/01/2009   Design of transducers for thermal cross-correlation flowmeter, Melecon 85, IEEE, 1985, Spain 21/12/2008   Modelling and MIMO Controller Design of Dense Powder Fluidised Beds, ISATRA13, ISA Transactions, vol. 35, June 1996 21/12/2008   A controller (for both SISO and MIMO modeling approaches) for a dust feeder of a fluidized bed rig has been proved feasible; the system was identified and the controller design and stability investigated,for both the open and closed loop controller configuration. The intrinsic physical complexity of the process flow itself lies in the fact that its parameters are susceptible to changes, i.e the powder flow is not homogeneous, but consists of concentrations and rarefications of particles. It is suggested that dust feeder design is the most interesting part in fluidized bed engineering. Further work should be done on the economics of the air and electrical power consumption in the fluidized bed.   http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V3P-3VTJB35-2&_user=10&_rdoc=1&_fmt=&_ori ...   More Information> CAPNEX An Expert System for Capnography (CO2 Respiration Analysis), Transactions of the Institute of Measurement and Control, Transactions of I M & C, Vol. 16, No. 5, 1994 21/12/2008

Pages: 1 | 2 | 3 | 4

Personal Information

Announcements

Research

Publications

Courses / Schedule