Until the 1950s, closed industrial applications were dismantled completely to conduct manual cleaning. However, we can clean filtration systems without utilizing time to dismantle them with chemical cleaning-in-Place. CIP includes the combination of chemicals, heat, and water, which will cause targeted fouling to be dissolved due to the exploited chemicals. However, a membrane needs high chemical resistance to withstand periodic chemical cleaning. As ceramic membranes possess high chemical resistance, CIP is a very efficient method to clean ceramic membranes of a liquid filtration application while maintaining high hygiene standards, essential in most fluid purification processes.
A water filtration system often has two attached CIP tanks, ensuring that targeted fouling can be removed. One tank contains a chemical alkaline, which removes objects such as grease and other organic compounds. The other tank contains a chemical acid used to remove objects such as minerals. Thus, the membranes can be cleaned in a wide range of pH.
During CIP, the whole filtration system shuts down, and the required chemicals are dosed into the system. The substances will then be circulated in the ceramic membranes with a crossflow pump to secure sufficient cleaning of all surfaces. The circulation time can be installed based upon specific requirements. To boost the effectiveness of the chemicals, the temperature is increased to approximately 40-60 ˚C. Depending on the water filtration system, the utilized CIP process, and the cleaning requirements, CIP typically takes 60-90 minutes. When the CIP process is done, the system is emptied using a substantial cleaning dissolution, and everything is led back to the water system’s process tank. CIP does not produce any chemical waste, which is not filtered.
Once a CIP is performed, the TMP and the permeability are restored.