Based on theoretical analysis

a laboratory test was carried out using several coalescing internals with different structures to investigate the effect of coalescing internals acting on the separating performance of oil-water gravity separator.Residence time

oil concentration distribution

separating efficiency

oil concentration and median particle diameter difference in front and at the back of different coalescing structures were comprehensively contrasted.Results indicate that

reticulate corrugated plate has a good coalescing effect for small droplets

which can significantly improve oil-water separating efficiency and shorten residence time.The effect of opening corrugated plate is worse

while joggled-lap corrugated plate is the worst among the three structures.It was found that excellent performance of the coalescing structures should satisfy three conditions.Firstly

having good oleophilic and hydrophobic property; secondly

having sufficient channels for oil droplets to rise upward; thirdly

having larger contact area for mixture phase.This work provides good foundation for further development of effective and compact oil-water gravity separation equipment.