Undesired aerosol formation in gas–liquid contact devices like for instance absorbers, quench coolers, or condensers, causes severe complications in industrial processes. Gas-liquid coalescing filter media, normally called fiber beds or candles filters, have received great attention in a wide variety of industrial applications, being a removal technology with one of the highest achievable droplet removal efficiency for submicron particles. This work deals with a novel multi-layer fiber bed, the GX mist eliminator, developed by AWS Corporation srl with improved performances compared to the conventional single-layer fiber bed commercialized by the Company. The novel fiber bed was conceived by means of a developed design model that takes into account constructional and operating parameters. The model was validated by experiments carried out on a lab scale unit. The performances of the novel fiber bed were then validated by experiments carried out in a pilot plant installed on a production line with plasticizer oil mist. For the laboratory scale the same oil was used to measure the separation efficiency and the pressure drop.