θ Ring filler, also known as Dixon Ring filler, Q Ring filler, is a small particle filler, made of metal mesh or perforated plate, the diameter and height of the filler is equal, the current use of materials are: stainless steel, brass, carbon steel, phosphor bronze and so on. Due to the capillary action of the wire mesh, the liquid can be well dispersed into a film, which is conducive to the mass transfer and heat transfer of gas and liquid, and can significantly unstable phenomenon such as groove flow. θ ring packing is mainly used in laboratory and small batch, high product separation process.

The pressure drop of θ ring packing is related to gas velocity, liquid spray quantity, weight of the system, surface tension, viscosity, characteristic factors of packing, as well as the pre-liquid flooding treatment of packing. The hysteresis of θ ring packing is larger than that of the same kind of solid packing, the surface wetting of θ ring is also higher than that of the general porcelain ring, and the film forming rate is higher, so the efficiency is also higher. The theoretical plate number of θ ring packing increases with the increase of gas velocity and decreases with the decrease of surface wettability of packing.