Abstract: Apparatus for removing contaminants from vapor utilizing a vertical flow passage through an adsorption bed vertically arranged in an upright housing. The adsorption bed may comprise several layers of gas-adsorbing media particularly suitable for removing corrosive gases such as hydrogen sulfide from air to be maintained at a desired contaminant-free level in a controlled environment. A perforated, conical member positioned in the lower end of the housing serves to support the media bed as well as to evenly distribute contaminated air, pressurized by a blower, upwardly through the media bed.A head section carrying a discharge segment having a purified vapor outlet is rotatably mounted on top of the housing. Rotary adjustment of the head section permits the purified air or other vapor to be discharged in a desired direction at a predetermined location.