The Effect of Valve Design on the Pressure Losses in a High-Pressure Homogenizer – an Improved Pressure Drop Correlation for Estimating Gap Height

Understanding how the design of high-pressure homogenizer valves influence pressure losses in the device is of general interest for performance optimizing, and of special importance for developing correlations for predicting gap heights and gap velocities. The traditionally used correlation is from 1975 and based on a limited experimental dataset on gaps that are longer and often of lower capacity than contemporary ones. This study uses well-validated best-practice CFD to develop an improved correlation for how homogenizing pressure depends on valve designs, extending previous investigations to also include the effect of seat and forcer incline angles. The suggested correlation differs substantially from the traditional ones, shows a marked effect on inlet and exit loss coefficients of Reynolds number and of inlet seat incline angle. For cases with Reynolds number comparable to pilot- and production-scale homogenizers, the gap height can be predicted to within 10% of the set value, using the suggested correlation.