A combined cleaning model for film-like soils with transition between cleaning mechanisms accounting for the effect of temperature and sodium hydroxide

Research output: Contribution to journalResearch articleContributedpeer-review

Abstract

Optimizing the cleaning time of thin soil layers is an omnipresent challenge in the food processing industry. One approach to address this problem is to identify different prototypical modes of soil removal, called cleaning mechanisms, and to simulate the cleaning process with a dedicated model for each cleaning mechanism. Industrial cleaning procedures, however, involve chemicals and non-constant operating conditions that cause the cleaning mechanism to change. In the present paper, a cleaning model combining different cleaning mechanisms is developed to represent the use of hot aqueous solution of sodium hydroxide as cleaning fluid, which is often employed in the food industry. The model includes a new formulation of a swelling sub-model based on a pseudo-diffusion approach and accounts for the transport of water, sodium hydroxide, and heat into the soil and the model switches automatically between the different cleaning mechanisms. Various validation cases for sub-models are presented. These allow to assess the most important interactions between different sub-models. The cleaning model is applied to the case of a soiled wall in a straight rectangular duct with turbulent flow characterized by bulk Reynolds numbers between 5000 and 30000 for ketchup and starch soils, and a flushing process of chocolate with laminar flow. Sodium hydroxide concentrations between 0 and 2 wt% and temperatures between 20 and 55 C are considered. Finally, in a further case study, the cleaning of a proteinaceous soil in a heat exchanger is simulated, where a simplified cleaning-in-place procedure is optimized using the new model.

Details

Original languageEnglish
Article number41
JournalHeat and Mass Transfer
Volume62
Issue number4
Publication statusPublished - 1 Apr 2026
Peer-reviewedYes

External IDs

ORCID /0000-0002-5148-9737/work/211001987
ORCID /0000-0001-9391-4407/work/211002683
ORCID /0000-0003-1653-5686/work/211003081
Scopus 105035386371

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