Abstract: When constant vacuum field is used for cleaning slender lumen instruments, the axial vacuum attenuation amplitude reaches 0.015~0.02 MPa due to the influence of conductivity limitation, which causes the uneven distribution of boiling mass transfer and the residual rate of pollutants at the end of lumen exceeds 25%, and restricts the development of current lumen cleaning technology. Therefore, an actively programmable dynamic vacuum field was proposed and established in this study. By utilizing gradient compensation, rate regulation, and temporal matching, this approach effectively resolves the mass transfer limitations arising from the passive adaptation of conventional static vacuum fields. Based on the difference of conductance of four typical cavities, a dynamic vacuum parameter design method was established, and a quantitative model of desorption rate and mass transfer uniformity was constructed by combining multi-field coupling simulation and experimental verification. The results show that, compared with the traditional constant vacuum method, the dynamic vacuum field can control the vacuum fluctuation in the whole cavity to 0.003 MPa, with a decrease of 70%-76%, the desorption rate of four kinds of cavity pollutants exceeds 90%, and the flow rate and volumetric mass transfer coefficient of cleaning solution are increased by 100%-135.7% and 33%-35%, respectively. The goodness-of-fit of the quantitative models were all over 0.9, and the average relative error was less than 4.2%.

Key words: dynamic vacuum field, vacuum gradient compensation, vacuum mass transfer enhancement, vacuum boiling control