Abstract: Apparatus for separating finely divided solids from gas is described comprising a generally cylindrical vessel having a gas inlet opening and a gas outlet opening, a solids inlet opening at the top of the vessel and a solids outlet opening at the bottom of the vessel. First generally cylindrical wall member having a diameter less than that of the vessel is disposed in the vessel to provide an elongated annular space lying between it and the vessel wall. The first cylindrical wall member is in sealing engagement with the top portion of the vessel. A second generally cylindrical wall member having a diameter less than the first wall member is disposed inside the first wall member to provide an elongated annular space between the two wall members which space is filled with a solid particulate contact material and which moves by gravity flow downwardly through the annular space.

Abstract: Finely divided solids are removed from a feed gas by passing the gas through an elongated annular mass of solid particulate contact material held between two generally concentric cylindrical walls. The outer wall is louvered having vanes outwardly inclined to the vertical at 15.degree. to 80.degree. and the louver openings are of such width that most of the particles of contact material are capable of passing through them. The inner wall is perforated to permit passage of gas through the wall and may be louvered similarly to the outer wall but having the louver vanes inwardly inclined. The finely divided solids are entrained or trapped in the mass of contact material which is moved downwardly through and out of the annular space between the two concentric cylindrical walls. The contact material is then treated to separate entrained finely divided solids and returned to the upper end of the annular space.