Abstract: Improved scrubber and method for removing particulate matter from hot flue gases, particularly flyash in a sludge incinerator, utilizes a plurality of cylindrical slotted wire screen canisters which are preferably mounted vertically in apertures in a plate in a chamber in which the hot gas moves vertically. The bottoms of the canisters may be closed so that the vertically moving gases will change direction at least twice as they move sideways through the screen slots and then vertically again inside the screens, or alternatively, the bottoms can be screens also with a baffle plate positioned under them to cause a change of direction of the gases. A spray nozzle in each canister keeps the spaced wires forming the sides and the slots wet so that a majority of the flyash will be captured and washed down the sides of the canisters while additional particles will be captured by the water wash spray inside the canisters.