MULTIINPUT, MULTIOUTPUT IDENTIFICATION OF A PILOT-PLANT CLIMBING FILMEVAPORATOR

The major aim of this research was to investigate the modeling and con trol of a 2.5 kW, 13.6 litres/hour pilot-plant climbing film evaporato r concentrating a sodium nitrate solution. This paper reports on a com parison of a range of models of the climbing film evaporator for the s pecific purpose of developing and designing industrially-viable proces s control systems. The simplest models of the evaporator were global l inear lumped-parameter models. Gain-scheduled linear lumped parameter models were identified to compensate for system non-linearity. Finally , full distributed-parameter models were derived for the evaporator, a nd their parameters identified.