Fault detection of a blending tank process using mixed integer linear programming

• Published in: IFAC Proceedings Volumes
• Main Authors: Salehpour, Soheil, Johansson, Andreas, Gustafsson, Thomas
• Format: Conference Object
• Language: English
• Published: Luleå tekniska universitet, Signaler och system 2009
• Subjects: Control Engineering; Reglerteknik; Malmberget
• Online Access: http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-39899; https://doi.org/10.3182/20091014-3-CL-4011.00040

The quality of iron ore pellets depends on many factors. One important issue is the mixing of binding material and slurry. It is assumed that proper mixing is achieved by keeping the material in the blender tank at an appropriate level to achieve a suitable residence time. The level of the blender is controlled by regulating the blender's hinged outflow-valve. Then, the modelling of the hinged valve is important, and the essential idea of this article is to find a method to use the process model and the available measured data to detect two detrimental conditions of the valve and warn the operators. These two conditions are: 1) The hinged valve is coated with slurry and therefore has to be cleaned to maintain its function. 2) Slurry is improperly distributed so that it does not cover the outflow valve, which then losesits authority over outflow. The valve behaviour is nonlinear and depends on the viscosity of the materials in the tank. Therefore, we use a change detection method based on Mixed Integer Linear Programming to estimate the time-varying parameters of the valve. Simulations with measurement data from the LKAB facility at Malmberget, Sweden, shows the viability of the algorithm. Godkänd; 2009; 20090627 (soheil) Modellering av komplexa dynamiska system