Abstract: An apparatus for separating and filtering pollutants from a fluid flow by using inertia to separate a proportion of the pollutants from the fluid flow passing through a constricted passage between a pair of filter elements to an outlet between the filter elements. The constricted passage causes the major portion of the fluid flow to be diverted to pass through the filter elements to the outlet in a direction whereby the filtered fluid flow exits into the outlet of the constricted passage. The apparatus also includes a device to periodically clean the filter elements whilst in position in the apparatus.