Multi-factorial Optimization of the Clean-In-Place program for a Fluid Bed Dryer after Drying of Ferrous Granules
Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
Aim: The aim of this project was to optimize the clean-in-place program for a fluid bed dryer used after drying wet ferrous granules, with focus on shortening the total time used for the program. This clean-in-place program has two critical objectives; removing a hard to clean iron residue on the inside surface of the fluid bed dryer by using an acidic detergent and thereafter removing the acidic detergent by rinsing steps.
Methods: The optimization was performed by down scaling the current clean-in-place program to laboratory scale, then varying the parameters volume and time by applying the statistical model Central Composite Circumscribe and use experimental design optimization to determine the influence of the parameters on the effect of cleanliness. Cleanliness in laboratory scale was assessed by visual inspection and UV/Vis spectroscopy. The cleanliness in production was determined by visual inspection, an iron test kit and a pH-meter. The results from the laboratory scale optimization lead to a new clean-in-place program that was evaluated twice in production after drying of ferrous batches.
Results and conclusions: The hard to clean iron residue could be recreated in laboratory scale. The optimization in laboratory scale showed that the parameter water was the most significant parameter for removal of the iron residue. The new clean-in-place program evaluated in production was 40% (approx. 110 min) shorter than the current clean-in-place program. The results of cleanliness varied after the new clean-in-place program had been used in production, not all hard to clean areas tested had approved results. Further optimization is needed to be able to clean after varying amount of granules in left in the fluid bed dryer after production ended. An interesting side results was that two steps dedicated to rinse out the detergent could be removed. This fact can lead to that even more rinsing steps can be excluded in the future clean-in-place programs.
Place, publisher, year, edition, pages
UPTEC K, ISSN 1650-8297 ; 15031
Engineering and Technology
IdentifiersURN: urn:nbn:se:uu:diva-263552OAI: oai:DiVA.org:uu-263552DiVA: diva2:860207
Master Programme in Chemical Engineering
Westin, UlrikaForsberg-Brikell, Ulrika
Björk, ErikMahlin, Denny