Capture Mechanisms of Oil Droplet Inside Spherical Particulate Beds

Abstract

Both primary and secondary oil dispersions may coexist during coalescence in spherical particulate beds. Therefore, the discussion of capture mechanisms, whatever the drop sizes, will be combined. The coalescence process of drop capture mechanisms will be considered in six types, namely indirect interception, direct interception, inertial impacting, sedimentation, London Van der Waal's forces and diffusion. This approach is convenient because most previous workers have defined these capture mechanisms. Although they have either disagreed as to the mechanisms postulated or found them inapplicable to the specific system under consideration. In this work, theoretical comparison of drop capture mechanisms demonstrated that indirect interception and London Van der Waal's mechanisms are most significant if the drops are >10 m. The diffusion mechanism may become significant for drops <10 m diameter.

Fibrous coalescence filtration in treating oily wastewater: A review

“…64,65 The following steps are involved in the coalescence filtration process using porous fibrous media as shown in Figures 4 and 5: (1) Transport of fluid having dispersed droplets (emulsion) to the filter; (2) Collision of droplets and subsequent coalescence (collision coalescence) or agglomeration or repulsion, 66 and the transport of merged droplets to the fiber; (3) Wetting coalescence processes comprising (a) droplet attachment to the fiber surface and (b) merging and enlargement of the droplets on to the fiber (wetting coalescence); and (4) Releasing of drops from the filter. 60,[67][68][69][70][71][72][73][74] The collision coalescence process is outlined in Figure 4, showing emulsion breakage and the formation of large droplets. The probability of an oil droplet intercepted by the fibers would be larger than the probability of its collision and coalescence with another droplet in the flow stream.…”

Separation of Water in Diesel Using Filter Media Containing Kapok Fibers

“…The water droplets with large sizes tended to contact with fibers by deformation. As the droplet size decreased, the water droplets tended to keep the spherical shape on fibers with slight deformation, resulting in lower probability of water droplet coalescence, since deformation of droplets hindered the coalescence [ 30 ]. In addition, contact time among smaller droplets was shorter, and it was more likely for small droplet to approach each other.…”