A filtration apparatus comprises a casing defining an inner cavity with an upper cylindrical portion and a lower hopper portion. An inlet feeds gas and solids into the inner cavity and causes movement of the solids in a downward spiral path in the casing. A solids outlet at a bottom of the lower hopper portion outlets the solids from the casing. A gas outlet exhausts gases from the casing. An annular arrangement of ports in a wall of the casing injects an other gas in the inner cavity. The ports are oriented to guide the other gas into following a partially vertical path into the inner cavity to disrupt the movement of the solids in the downward spiral path to allow a capture of the solid particles by the capturing solids. A gas source is connected to the arrangement of ports.