A filter apparatus and method for cleaning filter elements. The filter elements, each including a filter body with an external surface enclosing a filter passage, extend along a longitudinal axis of a vessel housing. A scraper element is disposed about the external surface of each filter body and travels along the longitudinal length of the filter body via a rotational screw to remove deposits. A lower air inlet is included on the vessel to loosen deposits on the filter surfaces, such as during or prior to scraping.