Influence of steam-induced wetting of food- and cosmetic-based contaminants on the efficiency of clean-in-place processes of containers

The cleaning of tanks or containers in the food and cosmetics industry with conventional tank cleaning systems requires a large amount of cleanser. Especially for swellable soiling, complete wetting of the surfaces and sufficient soaking of the soiling is advantageous for an efficient cleaning process. For soaking, only a small amount of cleanser needs to get in contact with the soil. Using conventional tank cleaning systems, significantly more cleanser is used during the soaking step than required. Flooding the tank with wet steam before cleaning to initiate the soaking process in a resource-saving manner addresses this issue. In this work, steam of varying saturation was injected into a test container to cause soaking and swelling of different soils before spray cleaning. The test setup consisted of a rectangular stainless-steel container with a volume of 105 L, a steam generator, a CIP-System, and a UV-camera sensor for monitoring the cleaning process. Using this test setup, the influence of a preliminary soaking step on the duration of the subsequent spray cleaning was investigated and compared with a conventional spray cleaning process. Flooding the tank with wet steam before spray cleaning reduced the spray cleaning time for most of the soiling. As a result, a reduction of up to 40% of the used cleanser was achieved.