Particle erosion wear in a high-pressure homogenizer – insights from DPM-CFD-erosion modelling

Abstract

High-pressure homogenizers (HPHs) are used extensively in food-, pharma-, and biotech processing. Erosion wear is a serious concern leading to high maintenance costs and downtime. Despite this, very little is known about how operating conditions and HPH design influence wear. Guidelines for optimizing design and operation are in great need. This contribution develops a relatively simple CFD-based approach to predict erosion wear in HPHs, with the long-term ambition of enabling model-based design and optimization. Comparison to previously published experimental data show that the model captures initial forcer wear. Moreover, the model is used to conclude on the effect of HPH seat inlet angle, particle properties, and operating conditions. The results suggest that erosion wear is reduced by using a lower seat inlet angle. Erosion wear also increases in proportion to the homogenizing pressure, which implies that care should be taken to design HPHs to reduce the utilized homogenizing pressure. The effects of (spherical) particle diameter and density on erosion are described in terms of a Stokes number; erosion wear is negligible if St < 1. Implications for the optimal design and operation of HPHs are discussed. As the first systematic investigation on erosion wear in HPH valves, the present numerical approach opens for improved design and operation of a unit operation with wide industrial application.