GB188539A - Improvements in filtering apparatus - Google Patents

Abstract

188,539. Timm, R. Nov. 18, 1921. Rotary filters.-Relates to vacuum filters of the rotary drum type having internal cells communicating with a common chamber located at one end of the drum, and provided with scrapers for the removal of residue clinging to the outer drum surface. According to the invention the filter drum a wholly or partially encloses a chamber r which communicates with both an antechamber m, and a receiving chamber p connected to an exhausting air-pump. The filter drum is covered with a permeable material b and is divided radially into chambers d. The filtered liquid flows into the antechamber and is conveyed by a siphon-pipe k to the exhausted chamber p at the opposite end of the drum. A flushing medium may be conveyed to the chambers d of the drum by a pipe l approximately the same cross section as the discharge pipe to avoid pressure differences in the axial direction. A branch-pipe n and connecting member o allow the contents of some of the drum-chambers to pass direct to a collecting vessel t without mixing with the filtrate in the antechamber. In a modification, an additional exhausting pipe conveys the filtrate to the same receiving chamber but withdraws it from the drum in the opposite axial direction to that of the main filtrate siphon pipe. In this form the antechamber is enclosed bv the drum surface and the former communicating chamber is only partially enclosed by the drum, the remainder being formed as a sleeve-like extension.