Gas–liquid coalescence filters are extensively
applied in
industrial fields, mainly to separate oil mist droplets that are carried
in gases. The traditional wettability treatment on the filter surface
can improve the filtration efficiency but usually also increases the
pressure drop. In this study, a surface modification method based
on tip patterns was proposed. Nonuniform wettability filter surfaces
with tip patterns were prepared by combining star-shaped molds and
spraying modification to explore the influence of key pattern parameters
on the performance of filters. In this way, industrial cartridges
were prepared based on the optimal modification parameters and their
filtration performance was analyzed and verified. The results showed
that liquid collection by the modified filters improved significantly
under the combined effect of the wettability driving force and Laplace
force produced by the shape gradient, while the steady-state pressure
drop decreased by 34.2–47.4% compared to the substrate filter.
The modifications facilitated an increase in the effective fiber surface
area and strengthened the droplet capture effect by diffusion. When
the tip angle was 50°, all of the modified filters achieved the
highest droplet filtration efficiency across different droplet size
intervals. When there were nine patterns at a 50° tip angle,
the modified filters achieved the optimal comprehensive filtration
performance, and the steady-state quality factor increased 3.1- and
3.4-fold for submicrometer and micrometer droplets, respectively,
compared to the substrate filter. Industrial cartridges were prepared
based on the optimal filters. Under different liquid-loading rates,
the modified cartridges had significantly higher efficiency and lower
resistance compared to the unmodified cartridge. The proposed pattern
modification method provides a direction for the design and development
of new high-performance coalescence components.