CONTROL TECHNIQUE FOR MULTISTEP WASHING PROCESS USING A PLURALITY OF CHEMICALS

摘要

Equipment and method for a system implementing a multistep washing process, with a chemical container (110A-110D) for each chemical (111A-111D) and means for conveying one chemical at a time from the container through a feed channel (120) to a washing object (100) and from the washing object through a return channel (130) back to the container. First and second sensors (122, 132) monitor a first parameter set in the feed channel (120) and a second parameter set in the return channel (130), respectively. Both parameter sets include parameter(s) indicating the purity of the chemical. A control center (150) includes calculation means (153) arranged to determine the mutual uniformity of the first and second monitored parameter sets. Action time of the chemical is determined on the basis of the mutual uniformity of the first and the second monitored parameter sets.